Metal-ligand complex catalyzed processes

ABSTRACT

This invention relates to a process for separating one or more phosphorus acidic compounds from a reaction product fluid containing said one or more phosphorus acidic compounds, a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand which process comprises treating said reaction product fluid with water sufficient to remove at least some amount of said one or more phosphorus acidic compounds from said reaction product fluid.

This application claims the benefit of provisional U.S. patentapplication Ser. Nos. 60/008289, 60/008763, 60/008284 and 60/008286, allfiled Dec. 6, 1995, and all of which are incorporated herein byreference.

BRIEF SUMMARY OF THE INVENTION Technical Field

This invention relates to improved metal-organophosphite ligand complexcatalyzed processes. More particularly this invention relates to the useof water to prevent and/or lessen hydrolytic degradation of theorganophosphite ligand and deactivation of the metal-organophosphiteligand complex catalyst of such processes.

Background of the Invention

It is known in the art that various products may be produced by reactingone or more reactants in the presence of an metal-organophosphite ligandcomplex catalyst. However, stabilization of the catalyst andorganophosphite ligand remains a primary concern of the art. Obviouslycatalyst stability is a key issue in the employment of any catalyst.Loss of catalyst or catalytic activity due to undesirable reactions ofthe highly expensive metal catalysts can be detrimental to theproduction of the desired product. Likewise degradation of theorganophosphite ligand employed during the process can lead to poisoningorganophosphite compounds or inhibitors or acidic byproducts that canlower the catalytic activity of the metal catalyst. Moreover, productioncosts of the product obviously increase when productivity of thecatalyst decreases.

For instance, a major cause of organophosphite ligand degradation andcatalyst deactivation of metal-organophosphite ligand complex catalyzedhydroformylation processes is due to the hydrolytic instability of theorganophosphite ligands. All organophosphites are susceptible tohydrolysis in one degree or another, the rate of hydrolysis oforganophosphites in general being dependent on the stereochemical natureof the organophosphite. In general, the bulkier the steric environmentaround the phosphorus atom, the slower the hydrolysis rate. For example,tertiary triorganophosphites such as triphenylphosphite are moresusceptible to hydrolysis than diorganophosphites, such as disclosed inU.S. Pat. No. 4,737,588, and organopolyphosphites such as disclosed inU.S. Pat. Nos. 4,748,261 and 4,769,498. Moreover, all such hydrolysisreactions invariably produce phosphorus acidic compounds which catalyzethe hydrolysis reactions. For example, the hydrolysis of a tertiaryorganophosphite produces a phosphonic acid diester, which ishydrolyzable to a phosphonic acid monoester, which in turn ishydrolyzable to H₃ PO₃ acid. Moreover, hydrolysis of the ancillaryproducts of side reactions, such as between a phosphonic acid diesterand the aldehyde or between certain organophosphite ligands and analdehyde, can lead to production of undesirable strong aldehyde acids,e.g., n-C₃ H₇ CH(OH)P(O)(OH)₂.

Indeed even highly desirable sterically-hindered organobisphosphiteswhich are not very hydrolyzable can react with the aldehyde product toform poisoning organophosphites, e.g., organomonophosphites, which arenot only catalytic inhibitors, but far more susceptible to hydrolysisand the formation of such aldehyde acid byproducts, e.g., hydroxy alkylphosphonic acids, as shown, for example, in U.S. Pat. Nos. 5,288,918 and5,364,950. Further, the hydrolysis of organophosphite ligands may beconsidered as being autocatalytic in view of the production of suchphosphorus acidic compounds, e.g., H₃ PO₃, aldehyde acids such ashydroxy alkyl phosphonic acids, H₃ PO₄ and the like, and if leftunchecked the catalyst system of the continuous liquid recyclehydroformylation process will become more and more acidic in time. Thusin time the eventual build-up of an unacceptable amount of suchphosphorus acidic materials can cause the total destruction of theorganophosphite present, thereby rendering the hydroformylation catalysttotally ineffective (deactivated) and the valuable rhodium metalsusceptible to loss, e.g., due to precipitation and/or depositing on thewalls of the reactor. Accordingly, a successful method for preventingand/or lessening such hydrolytic degradation of the organophosphiteligand and deactivation of the catalyst would be highly desirable to theart.

Disclosure of the Invention

It has now been discovered that water may be employed to effectivelyremove such phosphorus acidic compounds and thus prevent and/or lessenhydrolytic degradation of organophosphite ligands and deactivation ofmetal-organophosphite ligand complex catalysts that may occur over thecourse of time during processes which employ metal-organophosphiteligand complex catalysts. Although both water and acid are factors inthe hydrolysis of organophosphite ligands, it has been surprisinglydiscovered that reaction systems, e.g., hydroformylation, are moretolerant of higher levels of water than higher levels of acid. Thus, thewater can be used to remove acid and decrease the rate of loss oforganophosphite ligand by hydrolysis. It has also been surprisinglydiscovered that minimum loss of organophosphite ligand occurs when areaction product fluid containing a metal-organophosphite ligand complexcatalyst is contacted with water even at elevated temperatures.

This invention relates in part to a process for separating one or morephosphorus acidic compounds from a reaction product fluid containingsaid one or more phosphorus acidic compounds, a metal-organophosphiteligand complex catalyst and optionally free organophosphite ligand whichprocess comprises treating said reaction product fluid with watersufficient to remove at least some amount of said one or more phosphorusacidic compounds from said reaction product fluid.

This invention also relates in part to a process for stabilizing anorganophosphite ligand against hydrolytic degradation and/or ametal-organophosphite ligand complex catalyst against deactivation whichprocess comprises treating a reaction product fluid containing ametal-organophosphite ligand complex catalyst and optionally freeorganophosphite ligand and which also contains one or more phosphorusacidic compounds, with water sufficient to remove at least some amountof said one or more phosphorus acidic compounds from said reactionproduct fluid.

This invention further relates in part to a process for preventingand/or lessening hydrolytic degradation of an organophosphite ligandand/or deactivation of a metal-organophosphite ligand complex catalystwhich process comprises treating a reaction product fluid containing ametal-organophosphite ligand complex catalyst and optionally freeorganophosphite ligand and which also contains one or more phosphorusacidic compounds, with water sufficient to remove at least some amountof said one or more phosphorus acidic compounds from said reactionproduct fluid.

This invention yet further relates in part to an improved process whichcomprises reacting one or more reactants in the presence of ametal-organophosphite ligand complex catalyst and optionally freeorganophosphite ligand to produce a reaction product fluid comprisingone or more products, the improvement comprising preventing and/orlessening hydrolytic degradation of any said organophosphite ligand anddeactivation of said metal-organophosphite ligand complex catalyst bytreating at least a portion of said reaction product fluid derived fromsaid process and which also contains phosphorus acidic compounds formedduring said process with water sufficient to remove at least some amountof the phosphorus acidic compounds from said reaction product fluid.

This invention also relates in part to an improved process for producingone or more products which comprises (i) reacting in at least onereaction zone one or more reactants in the presence of ametal-organophosphite ligand complex catalyst and optionally freeorganophosphite ligand to produce a reaction product fluid comprisingone or more products and (ii) separating in at least one separation zoneor in said at least one reaction zone the one or more products from saidreaction product fluid, the improvement comprising preventing and/orlessening hydrolytic degradation of any said organophosphite ligand anddeactivation of said metal-organophosphite ligand complex catalyst by(a) withdrawing from said at least one reaction zone or said at leastone separation zone at least a portion of said reaction product fluidderived from said process and which also contains phosphorus acidiccompounds formed during said process, (b) treating in at least onescrubber zone at least a portion of the withdrawn reaction product fluidderived from said process and which also contains phosphorus acidiccompounds formed during said process with water sufficient to remove atleast some amount of the phosphorus acidic compounds from said reactionproduct fluid, and (c) returning the treated reaction product fluid tosaid at least one reaction zone or said at least one separation zone.

This invention further relates in part to an improved process forproducing one or more products which comprises (i) reacting in at leastone reaction zone one or more-reactants in the presence of ametal-organophosphite ligand complex catalyst and optionally freeorganophosphite ligand to produce a reaction product fluid comprisingone or more products and (ii) separating in at least one separation zoneor in said at least one reaction zone the one or more products from saidreaction product fluid, the improvement comprising preventing and/orlessening hydrolytic degradation of any said organophosphite ligand anddeactivation of said metal-organophosphite ligand complex catalyst bytreating at least a portion of said reaction product fluid derived fromsaid process and which also contains phosphorus acidic compounds formedduring said process by introducing water into said at least one reactionzone and/or said at least one separation zone sufficient to remove atleast some amount of the phosphorus acidic compounds from said reactionproduct fluid.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a simplified process flow diagram of a process for recoveringand returning one or more aldehydes removed by water extraction to thehydroformylation process in accordance with this invention.

DETAILED DESCRIPTION General Processes

The processes of this invention may be asymmetric or non-asymmetric, thepreferred processes being non-asymmetric, and may be conducted in anycontinuous or semi-continuous fashion and may involve any catalystliquid and/or gas recycle operation desired. The particular processesfor producing products from one or more reactants, as well as thereaction conditions and ingredients of the processes are not criticalfeatures of this invention. The processing techniques of this inventionmay correspond to any of the known processing techniques heretoforeemployed in conventional processes. For instance, the processes can beconducted in either the liquid or gaseous states and in a continuous,semi-continuous or batch fashion and involve a liquid recycle and/or gasrecycle operation or a combination of such systems as desired. Likewise,the manner or order of addition of the reaction ingredients, catalystand solvent are also not critical and may be accomplished in anyconventional fashion. As used herein, the term "reaction product fluid"is contemplated to include, but not limited to, a reaction mixturecontaining an amount of any one or more of the following: (a) ametal-organophosphite ligand complex catalyst, (b) free organophosphiteligand, (c) one or more phosphorus acidic compounds formed in thereaction, (d) product formed in the reaction, (e) unreacted reactants,and (f) an organic solubilizing agent for said metal-organophosphiteligand complex catalyst and said free organophosphite ligand. Thereaction product fluid encompasses, but is not limited to, (a) thereaction medium in the reaction zone, (b) the reaction medium stream onits way to the separation zone, (c) the reaction medium in theseparation zone, (d) the recycle stream between the separation zone andthe reaction zone, (e) the reaction medium withdrawn from the reactionzone or separation zone for treatment with the water, (f) the withdrawnreaction medium treated with the water, (g) the treated reaction mediumreturned to the reaction zone or separation zone, and (h) reactionmedium in external cooler.

This invention encompasses the carrying out of known conventionalsyntheses in a conventional fashion employing a metal-organophosphiteligand complex catalyst in which the metal-organophosphite ligandcomplex catalyst containing reaction product fluid derived from saidprocess and which also contains phosphorus acidic compounds formedduring said process is treated with water in order to neutralize andremove at least some amount of the phosphorus acidic compounds from saidmetal-organophosphite ligand complex catalyst containing reactionproduct fluid to prevent and/or lessen hydrolytic degradation of theorganophosphite ligand and deactivation of the metal-organophosphiteligand complex catalyst.

Illustrative processes include, for example, hydroformylation,hydroacylation (intramolecular and intermolecular), hydrocyanation,hydroamidation, hydroesterification, aminolysis, alcoholysis,carbonylation, olefin isomerization, transfer hydrogenation and thelike. Preferred processes involve the reaction of organic compounds withcarbon monoxide, or with carbon monoxide and a third reactant, e.g.,hydrogen, or with hydrogen cyanide, in the presence of a catalyticamount of a metal-organophosphite ligand complex catalyst. The mostpreferred processes include hydroformylation, hydrocyanation andcarbonylation.

Hydroformylation can be carried out in accordance with conventionalprocedures known in the art. For example, aldehydes can be prepared byreacting an olefinic compound, carbon monoxide and hydrogen underhydroformylation conditions in the presence of a metal-organophosphiteligand complex catalyst described herein. Alternatively,hydroxyaldehydes can be prepared by reacting an epoxide, carbon monoxideand hydrogen under hydroformylation conditions in the presence of ametal-organophosphite ligand complex catalyst described herein. Thehydroxyaldehyde can be hydrogenated to a diol, e.g.,hydroxypropionaldehyde can be hydrogenated to propanediol.Hydroformylation processes are described more fully hereinbelow.

Intramolecular hydroacylation can be carried out in accordance withconventional procedures known in the art. For example, aldehydescontaining an olefinic group 3 to 7 carbons removed can be converted tocyclic ketones under hydroacylation conditions in the presence of ametal-organophosphite ligand complex catalyst described herein.

Intermolecular hydroacylation can be carried out in accordance withconventional procedures known in the art. For example, ketones can beprepared by reacting an olefin and an aldehyde under hydroacylationconditions in the presence of a metal-organophosphite ligand complexcatalyst described herein.

Hydrocyanation can be carried out in accordance with conventionalprocedures known in the art. For example, nitrile compounds can beprepared by reacting an olefinic compound and hydrogen cyanide underhydrocyanation conditions in the presence of a metal-organophosphiteligand complex catalyst described herein. A preferred hydrocyanationprocess involves reacting a nonconjugated acyclic aliphatic monoolefin,a monoolefin conjugated to an ester group, e.g., methyl pent-2-eneoate,or a monoolefin conjugated to a nitrile group, e.g., 3-pentenenitrile,with a source of hydrogen cyanide in the presence of a catalystprecursor composition comprising zero-valent nickel and a bidentatephosphite ligand to produce a terminal organonitrile, e.g.,adiponitrile, alkyl 5-cyanovalerate or 3-(perfluoroalkyl)propionitrile.Preferably, the reaction is carried out in the presence of a Lewis acidpromoter. Illustrative hydrocyanation processes are disclosed in U.S.Pat. No. 5,523,453 and WO 95/14659, the disclosures of which areincorporated herein by reference.

Hydroamidation can be carried out in accordance with conventionalprocedures known in the art. For example, amides can be prepared byreacting an olefin, carbon monoxide and a primary or secondary amine orammonia under hydroamidation conditions in the presence of ametal-organophosphite ligand complex catalyst described herein.

Hydroesterification can be carried out in accordance with conventionalprocedures known in the art. For example, esters can be prepared byreacting an olefin, carbon monoxide and an alcohol underhydroesterification conditions in the presence of ametal-organophosphite ligand complex catalyst described herein.

Aminolysis can be carried out in accordance with conventional proceduresknown in the art. For example, amines can be prepared by reacting anolefin with a primary or secondary amine under aminolysis conditions inthe presence of a metal-organophosphite ligand complex catalystdescribed herein.

Alcoholysis can be carried out in accordance with conventionalprocedures known in the art. For example, ethers can be prepared byreacting an olefin with an alcohol under alcoholysis conditions in thepresence of a metal-organophosphite ligand complex catalyst describedherein.

Carbonylation can be carried out in accordance with conventionalprocedures known in the art. For example, lactones can be prepared bytreatment of allylic alcohols with carbon monoxide under carbonylationconditions in the presence of a metal-organophosphite ligand complexcatalyst described herein.

Isomerization can be carried out in accordance with conventionalprocedures known in the art. For example, allylic alcohols can beisomerized under isomerization conditions to produce aldehydes in thepresence of a metal-organophosphite ligand complex catalyst describedherein.

Transfer hydrogenation can be carried out in accordance withconventional procedures known in the art. For example, alcohols can beprepared by reacting a ketone and an alcohol under transferhydrogenation conditions in the presence of a metal-organophosphiteligand complex catalyst described herein.

The permissible starting material reactants encompassed by the processesof this invention are, of course, chosen depending on the particularprocess desired. Such starting materials are well known in the art andcan be used in conventional amounts in accordance with conventionalmethods. Illustrative starting material reactants include, for example,substituted and unsubstituted aldehydes (intramolecular hydroacylation),olefins (hydroformylation, carbonylation, intermolecular hydroacylation,hydrocyanation, hydroamidation, hydroesterification, aminolysis,alcoholysis), ketones (transfer hydrogenation), epoxides(hydroformylation, hydrocyanation), alcohols (carbonylation) and thelike. Illustrative of suitable reactants for effecting the processes ofthis invention are set out in Kirk-Othmer, Encyclopedia of ChemicalTechnology, Fourth Edition, 1996, the pertinent portions of which areincorporated herein by reference.

Illustrative metal-organophosphite ligand complex catalysts employablein the processes encompassed by this invention as well as methods fortheir preparation are well known in the art and include those disclosedin the below mentioned patents. In general such catalysts may bepreformed or formed in situ as described in such references and consistessentially of metal in complex combination with an organophosphiteligand. The active species may also contain carbon monoxide and/orhydrogen directly bonded to the metal.

The catalyst useful in the processes includes a metal-organophosphiteligand complex catalyst which can be optically active or non-opticallyactive. The permissible metals which make up the metal-organophosphiteligand complexes include Group 8, 9 and 10 metals selected from rhodium(Rh), cobalt (Co), iridium (Ir), ruthenium (Ru), iron (Fe), nickel (Ni),palladium (Pd), platinum (Pt), osmium (Os) and mixtures thereof, withthe preferred metals being rhodium, cobalt, iridium and ruthenium, morepreferably rhodium, cobalt and ruthenium, especially rhodium. Otherpermissible metals include Group 11 metals selected from copper (Cu),silver (Ag), gold (Au) and mixtures thereof, and also Group 6 metalsselected from chromium (Cr), molybdenum (Mo), tungsten (W) and mixturesthereof. Mixtures of metals from Groups 6, 8, 9, 10 and 11 may also beused in this invention. The permissible organophosphite ligands whichmake up the metal-organophosphite ligand complexes and freeorganophosphite ligand include mono-, di-, tri- and higherpolyorganophosphites. Mixtures of such ligands may be employed ifdesired in the metal-organophosphite ligand complex catalyst and/or freeligand and such mixtures may be the same or different. This invention isnot intended to be limited in any manner by the permissibleorganophosphite ligands or mixtures thereof. It is to be noted that thesuccessful practice of this invention does not depend and is notpredicated on the exact structure of the metal-organophosphite ligandcomplex species, which may be present in their mononuclear, dinuclearand/or higher nuclearity forms. Indeed, the exact structure is notknown. Although it is not intended herein to be bound to any theory ormechanistic discourse, it appears that the catalytic species may in itssimplest form consist essentially of the metal in complex combinationwith the organophosphite ligand and carbon monoxide and/or hydrogen whenused.

The term "complex" as used herein and in the claims means a coordinationcompound formed by the union of one or more electronically richmolecules or atoms capable of independent existence with one or moreelectronically poor molecules or atoms, each of which is also capable ofindependent existence. For example, the organophosphite ligandsemployable herein may possess one or more phosphorus donor atoms, eachhaving one available or unshared pair of electrons which are eachcapable of forming a coordinate covalent bond independently or possiblyin concert (e.g., via chelation) with the metal. Carbon monoxide (whichis also properly classified as a ligand) can also be present andcomplexed with the metal. The ultimate composition of the complexcatalyst may also contain an additional ligand, e.g., hydrogen or ananion satisfying the coordination sites or nuclear charge of the metal.Illustrative additional ligands include, for example, halogen (Cl, Br,I), alkyl, aryl, substituted aryl, acyl, CF₃, C₂ F₅, CN, (R)₂ PO andRP(O)(OH)O (wherein each R is the same or different and is a substitutedor unsubstituted hydrocarbon radical, e.g., the alkyl or aryl), acetate,acetylacetonate, SO₄, PF₄, PF₆, NO₂, NO₃, CH₃ O, CH₂ ═CHCH₂, CH₃CH═CHCH₂, C₆ H₅ CN, CH₃ CN, NH₃, pyridine, (C₂ H₅)₃ N, mono-olefins,diolefins and triolefins, tetrahydrofuran, and the like. It is of courseto be understood that the complex species are preferably free of anyadditional organic ligand or anion that might poison the catalyst orhave an undue adverse effect on catalyst performance. It is preferred inthe metal-organophosphite ligand complex catalyzed processes, e.g.,hydroformylation, that the active catalysts be free of halogen andsulfur directly bonded to the metal, although such may not be absolutelynecessary.

The number of available coordination sites on such metals is well knownin the art. Thus the catalytic species may comprise a complex catalystmixture, in their monomeric, dimeric or higher nuclearity forms, whichare preferably characterized by at least one organophosphite-containingmolecule complexed per one molecule of metal, e.g., rhodium. Forinstance, it is considered that the catalytic species of the preferredcatalyst employed in a hydroformylation reaction may be complexed withcarbon monoxide and hydrogen in addition to the organophosphite ligandsin view of the carbon monoxide and hydrogen gas employed by thehydroformylation reaction.

The organophosphites that may serve as the ligand of themetal-organophosphite ligand complex catalyst and/or free ligand of theprocesses and reaction product fluids of this invention may be of theachiral (optically inactive) or chiral (optically active) type and arewell known in the art. By "free ligand" is meant ligand that is notcomplexed with (tied to or bound to) the metal, e.g., metal atom, of thecomplex catalyst. As noted herein, the processes of this invention andespecially the hydroformylation process may be carried out in thepresence of free organophosphite ligand. Achiral organophosphites arepreferred.

Among the organophosphites that may serve as the ligand of themetal-organophosphite ligand complex catalyst containing reactionproduct fluids of this invention and/or any free organophosphite ligandthat might also be present in said reaction product fluids aremonoorganophosphite, diorganophosphite, triorganophosphite andorganopolyphosphite compounds. Such organophosphite ligands employablein this invention and/or methods for their preparation are well known inthe art.

Representative monoorganophosphites may include those having theformula: ##STR1## wherein R¹ represents a substituted or unsubstitutedtrivalent hydrocarbon radical containing from 4 to 40 carbon atoms orgreater, such as trivalent acyclic and trivalent cyclic radicals, e.g.,trivalent alkylene radicals such as those derived from1,2,2-trimethylolpropane and the like, or trivalent cycloalkyleneradicals such as those derived from 1,3,5-trihydroxycyclohexane, and thelike. Such monoorganophosphites may be found described in greaterdetail, for example, in U.S. Pat. No. 4,567,306, the disclosure of whichis incorporated herein by reference thereto.

Representative diorganophosphites may include those having the formula:##STR2## wherein R² represents a substituted or unsubstituted divalenthydrocarbon radical containing from 4 to 40 carbon atoms or greater andW represents a substituted or unsubstituted monovalent hydrocarbonradical containing from 1 to 18 carbon atoms or greater.

Representative substituted and unsubstituted monovalent hydrocarbonradicals represented by W in the above Formula (II) include alkyl andaryl radicals, while representative substituted and unsubstituteddivalent hydrocarbon radicals represented by R² include divalent acyclicradicals and divalent aromatic radicals. Illustrative divalent acyclicradicals include, for example, alkylene, alkylene-oxy-alkylene,alkylene-NR⁴ -alkylene wherein R⁴ is hydrogen or a substituted orunsubstituted monovalent hydrocarbon radical, e.g., an alkyl radicalhaving 1 to 4 carbon atoms; alkylene-S-alkylene, and cycloalkyleneradicals, and the like. The more preferred divalent acyclic radicals arethe divalent alkylene radicals such as disclosed more fully, forexample, in U.S. Pat. Nos. 3,415,906 and 4,567,302 and the like, thedisclosures of which are incorporated herein by reference. Illustrativedivalent aromatic radicals include, for example, arylene, bisarylene,arylene-alkylene, arylene-alkylene-arylene, arylene-oxy-arylene,arylene-NR⁴ -arylene wherein R⁴ is as defined above, arylene-S-arylene,and arylene-S-alkylene, and the like. More preferably R² is a divalentaromatic radical such as disclosed more fully, for example, in U.S. Pat.Nos. 4,599,206, 4,717,775, 4,835,299, and the like, the disclosures ofwhich are incorporated herein by reference.

Representative of a more preferred class of diorganophosphites are thoseof the formula: ##STR3## wherein W is as defined above, each Ar is thesame or different and represents a substituted or unsubstituted arylradical, each y is the same or different and is a value of 0 or 1, Qrepresents a divalent bridging group selected from --C(R³)₂ --, --O--,--S--, --NR⁴⁻⁻, Si(R⁵)₂ --and --CO--, wherein each R³ is the same ordifferent and represents hydrogen, an alkyl radical having from 1 to 12carbon atoms, phenyl, tolyl, and anisyl, R⁴ is as defined above, each R⁵is the same or different and represents hydrogen or a methyl radical,and m is a value of 0 or 1. Such diorganophosphites are described ingreater detail, for example, in U.S. Pat. Nos. 4,599,206, 4,717,775, and4,835,299 the disclosures of which are incorporated herein by reference.

Representative triorganophosphites may include those having the formula:##STR4## wherein each R⁶ is the same or different and is a substitutedor unsubstituted monovalent hydrocarbon radical e.g., an alkyl,cycloalkyl, aryl, alkaryl and aralkyl radicals which may contain from 1to 24 carbon atoms. Illustrative triorganophosphites include, forexample, trialkyl phosphites, dialkylaryl phosphites, alkyldiarylphosphites, triaryl phosphites, and the like, such as, for example,trimethyl phosphite, triethyl phosphite, butyldiethyl phosphite,tri-n-propyl phosphite, tri-n-butyl phosphite, tri-2-ethylhexylphosphite, tri-n-octyl phosphite, tri-n-dodecyl phosphite,dimethylphenyl phosphite, diethylphenyl phosphite, methyldiphenylphosphite, ethyldiphenyl phosphite, triphenyl phosphite, trinaphthylphosphite, bis(3,6,8-tri-t-butyl-2-naphthyl)methylphosphite,bis(3,6,8-tri-t-butyl-2-naphthyl)cyclohexylphosphite,tris(3,6-di-t-butyl-2-naphthyl)phosphite,bis(3,6,8-tri-t-butyl-2-naphthyl)(4-biphenyl)phosphite,bis(3,6,8-tri-t-butyl-2-naphthyl)phenylphosphite,bis(3,6,8-tri-t-butyl-2-naphthyl)(4-benzoylphenyl)phosphite,bis(3,6,8-tri-t-butyl-2-naphthyl)(4-sulfonylphenyl)phosphite, and thelike. The most preferred triorganophosphite is triphenylphosphite. Suchtriorganophosphites are described in greater detail, for example, inU.S. Pat. Nos. 3,527,809 and 5,277,532, the disclosures of which areincorporated herein by reference.

Representative organopolyphosphites contain two or more tertiary(trivalent) phosphorus atoms and may include those having the formula:##STR5## wherein X represents a substituted or unsubstituted n-valentorganic bridging radical containing from 2 to 40 carbon atoms, each R⁷is the same or different and represents a divalent organic radicalcontaining from 4 to 40 carbon atoms, each R⁸ is the same or differentand represents a substituted or unsubstituted monovalent hydrocarbonradical containing from 1 to 24 carbon atoms, a and b can be the same ordifferent and each have a value of 0 to 6, with the proviso that the sumof a+b is 2 to 6 and n equals a+b. Of course it is to be understood thatwhen a has a value of 2 or more, each R⁷ radical may be the same ordifferent. Each R⁸ radical may also be the same or different any givencompound.

Representative n-valent (preferably divalent) organic bridging radicalsrepresented by X and representative divalent organic radicalsrepresented by R⁷ above, include both acyclic radicals and aromaticradicals, such as alkylene, alkylene-Q_(m) -alkylene, cycloalkylene,arylene, bisarylene, arylene-alkylene, and arylene-(CH₂)_(y) --Q_(m)--(CH₂)_(y) -arylene radicals, and the like, wherein each Q, y and m areas defined above in Formula (III). The more preferred acyclic radicalsrepresented by X and R⁷ above are divalent alkylene radicals, while themore preferred aromatic radicals represented by X and R⁷ above aredivalent arylene and bisarylene radicals, such as disclosed more fully,for example, in U.S. Pat. Nos. 4,769,498; 4,774,361: 4,885,401;5,179,055; 5,113,022; 5,202,297; 5,235,113; 5,264,616 and 5,364,950, andEuropean Patent Application Publication No. 662,468, and the like, thedisclosures of which are incorporated herein by reference.Representative preferred monovalent hydrocarbon radicals represented byeach R⁸ radical above include alkyl and aromatic radicals.

Illustrative preferred organopolyphosphites may include bisphosphitessuch as those of Formulas (VI) to (VIII) below: ##STR6## wherein eachR⁷, R⁸ and X of Formulas (VI) to (VIII) are the same as defined abovefor Formula (V). Preferably each R⁷ and X represents a divalenthydrocarbon radical selected from alkylene, arylene,arylene-alkylene-arylene, and bisarylene, while each R⁸ radicalrepresents a monovalent hydrocarbon radical selected from alkyl and arylradicals. Organophosphite ligands of such Formulas (V) to (VIII) may befound disclosed, for example, in U.S. Pat. Nos. 4,668,651; 4,748,261;4,769,498; 4,774,361; 4,885,401; 5,113,022; 5,179,055; 5,202,297;5,235,113; 5,254,741; 5,264,616; 5,312,996; 5,364,950; and 5,391,801;the disclosures of all of which are incorporated herein by reference.

Representative of more preferred classes of organobisphosphites arethose of the following Formulas (IX) to (XI) ##STR7## wherein Ar, Q, R⁷,R⁸ X m, and y are as defined above. Most preferably X represents adivalent aryl--(CH₂)_(y) --(Q)_(m) --(CH₂)_(y) --aryl radical whereineach y individually has a value of 0 or 1; m has a value of 0 or 1 and Qis --O--, --S-- or --C(R³)₂ where each R³ is the same or different andrepresents hydrogen or a methyl radical. More preferably each alkylradical of the above defined R⁸ groups may contain from 1 to 24 carbonatoms and each aryl radical of the above-defined Ar, X, R⁷ and R⁸ groupsof the above Formulas (IX) to (XI) may contain from 6 to 18 carbon atomsand said radicals may be the same or different, while the preferredalkylene radicals of X may contain from 2 to 18 carbon atoms and thepreferred alkylene radicals of R⁷ may contain from 5 to 18 carbon atoms.In addition, preferably the divalent Ar radicals and divalent arylradicals of X of the above formulas are phenylene radicals in which thebridging group represented by --CH₂)_(y) --(Q)_(m) --CH₂)_(y) -- isbonded to said phenylene radicals in positions that are ortho to theoxygen atoms of the formulas that connect the phenylene radicals totheir phosphorus atom of the formulae. It is also preferred that anysubstituent radical when present on such phenylene radicals be bonded inthe para and/or ortho position of the phenylene radicals in relation tothe oxygen atom that bonds the given substituted phenylene radical toits phosphorus atom.

Of course any of the R¹, R², R⁶, R⁷, R⁸, W, X, Q and Ar radicals of suchorganophosphites of Formulas (I) to (XI) above may be substituted ifdesired, with any suitable substituent containing from 1 to 30 carbonatoms that does not unduly adversely affect the desired result of theprocess of this invention. Substituents that may be on said radicals inaddition of course to corresponding hydrocarbon radicals such as alkyl,aryl, aralkyl, alkaryl and cyclohexyl substituents, may include forexample silyl radicals such as --Si(R¹⁰)₃ ; amino radicals such as--N(R¹⁰)₂ ; phosphine radicals such as -aryl-P(R¹⁰)₂ ; acyl radicalssuch as --C(O)R¹⁰ acyloxy radicals such as --OC(O)R¹⁰ ; amido radicalssuch as --CON(R¹⁰)₂ and --N(R¹⁰)COR¹⁰ ; sulfonyl radicals such as --SO₂R¹⁰, alkoxy radicals such as --OR¹⁰ ; sulfinyl radicals such as --SOR¹⁰,sulfenyl radicals such as --SR¹⁰, phosphonyl radicals such as--P(O)(R¹⁰)₂, as well as halogen, nitro, cyano, trifluoromethyl, hydroxyradicals, and the like, wherein each R¹⁰ radical individually representsthe same or different monovalent hydrocarbon radical having from 1 to 18carbon atoms (e.g., alkyl, aryl, aralkyl, alkaryl and cyclohexylradicals), with the proviso that in amino substituents such as --N(R¹⁰)₂each R¹⁰ taken together can also represent a divalent bridging groupthat forms a heterocyclic radical with the nitrogen atom, and in amidosubstituents such as --C(O)N(R¹⁰)₂ and --N(R¹⁰)COR¹⁰ each R¹⁰ bonded toN can also be hydrogen. Of course it is to be understood that any of thesubstituted or unsubstituted hydrocarbon radicals groups that make up aparticular given organophosphite may be the same or different.

More specifically illustrative substituents include primary, secondaryand tertiary alkyl radicals such as methyl, ethyl, n-propyl, isopropyl,butyl, sec-butyl, t-butyl, neo-pentyl, n-hexyl, amyl, sec-amyl, t-amyl,iso-octyl, decyl, octadecyl, and the like; aryl radicals such as phenyl,naphthyl and the like; aralkyl radicals such as benzyl, phenylethyl,triphenylmethyl, and the like; alkaryl radicals such as tolyl, xylyl,and the like; alicyclic radicals such as cyclopentyl, cyclohexyl,1-methylcyclohexyl, cyclooctyl, cyclohexylethyl, and the like; alkoxyradicals such as methoxy, ethoxy, propoxy, t-butoxy, --OCH₂ CH₂ OCH₃,--O(CH₂ CH₂)₂ OCH₃, --O(CH₂ CH₂)₃ OCH₃, and the like; aryloxy radicalssuch as phenoxy and the like; as well as silyl radicals such as--Si(CH₃)₃, --Si(OCH₃)₃, --Si(C₃ H₇)₃, and the like; amino radicals suchas --NH₂, --N(CH₃)₂, --NHCH₃, --NH(C₂ H₅), and the like; arylphosphineradicals such as --P(C₆ H₅)₂, and the like; acyl radicals such as--C(O)CH₃, --C(O)C₂ H₅, --C(O)C₆ H₅, and the like; carbonyloxy radicalssuch as --C(O)OCH₃ and the like; oxycarbonyl radicals such as --O(CO)C₆H₅, and the like; amido radicals such as --CONH₂, --CON(CH₃)₂,--NHC(O)CH₃, and the like; sulfonyl radicals such as --S(O)₂ C₂ H₅ andthe like; sulfinyl radicals such as --S(O)CH₃ and the like; sulfenylradicals such as --SCH₃, --SC₂ H₅, --SC₆ H₅, and the like; phosphonylradicals such as --P(O)(C₆ H₅)₂, --P(O)(CH₃)₂, --P(O)(C₂ H₅)₂, --P(O)(C₃H₇)₂, --P(O)(C₄ H₉)₂, --P(O)(C₆ H₁₃)₂,--P(O)CH3(C₆ H₅), --P(O)(H)(C₆H5), and the like.

Specific illustrative examples of such organophosphite ligands includethe following:2-t-butyl-4-methoxyphenyl(3,3'-di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)phosphitehaving the formula: ##STR8##methyl(3,3'-di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)phosphitehaving the formula: ##STR9## 6,6'- 4,4'-bis(1,1-dimethylethyl)-1,1'-binaphthyl!-2,2'-diyl!bis(oxy)!bis-dibenzo d,f!1,3,2!-dioxaphosphepin having the formula: ##STR10## 6,6'-3,3'-bis(1,1-dimethylethyl)-5,5'-dimethoxy-1,1'-biphenyl!-2,2'-diyl!bis(oxy)!bis-dibenzo d,f! 1,3,2!dioxaphosphepinhaving the formula: ##STR11## 6,6'-3,3',5,5'-tetrakis(1,1-dimethylpropyl)-1,1'-biphenyl!-2,2'-diyl!bis(oxy)!bis-dibenzo d,f! 1,3,2!dioxaphosphepinhaving the formula: ##STR12## 6,6'-3,3',5,5'-tetrakis(1,1-dimethylethyl)-1,1'-biphenyl!-2,2'-diyl!bis(oxy)!bis-dibenzod,f! 1,3,2!-dioxaphosphepin having the formula: ##STR13## (2R,4R)-di2,2'-(3,3',5,5'-tetrakis-tert-amyl-1,1'-biphenyl)!-2,4-pentyldiphosphitehaving the formula: ##STR14## (2R,4R)-di2,2'-(3,3',5,5'-tetrakis-tert-butyl-1,1'-biphenyl)!-2,4-pentyldiphosphitehaving the formula: ##STR15## (2R,4R)-di2,2'-(3,3'-di-amyl-5,5'-dimethoxy-1,1'-biphenyl)!-2,4-pentyldiphosphitehaving the formula: ##STR16## (2R,4R)-di2,2'-(3,3'-di-tert-butyl-5,5'-dimethyl-1,1'-biphenyl)!-2,4-pentyldiphosphitehaving the formula: ##STR17## (2R,4R)-di2,2'-(3,3'-di-tert-butyl-5,5'-diethoxy-1,1'-biphenyl)!-2,4-pentyldiphosphite having the formula: ##STR18## (2R,4R)-di2,2'-(3,3'-di-tert-butyl-5,5'-diethyl-1,1'-biphenyl)!-2,4-pentyldiphosphitehaving the formula: ##STR19## (2R,4R)-di2,2'-(3,3'-di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl)!-2,4-pentyldiphosphitehaving the formula: ##STR20## 6- 2'-(4,6-bis(1,1-dimethylethyl)-1,3,2-benzodioxaphosphol-2-yl)oxy!-3,3'-bis(1,1-dimethylethyl)-5,5'-dimethoxy 1,1 '-biphenyl!-2-yl!oxy!-4,8-bis(1,1-dimethylethyl)-2,10-dimethoxydibenzo d,f! 1,3,2!dioxa-phosphepinhaving the formula: ##STR21## 6- 2'-1,3,2-benzodioxaphosphol-2-yl)oxy!-3,3'-bis(1,1-dimethylethyl)-5,5'-dimethoxy1,1'-biphenyl!-2-yl!oxy!-4,8-bis(1,1-dimethylethyl)-2,10-dimethoxydibenzod,f! 1,3,2!dioxaphosphepin having the formula: ##STR22## 6- 2'-(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)oxy!-3,3'-bis(1,1-dimethylethyl)-5,5'-dimethoxy1,1'-biphenyl!-2-yl!oxy!-4,8-bis(1,1-dimethylethyl)-2,10-dimethoxydibenzod,f! 1,3,2!dioxaphosphepin having the formula: ##STR23## 2'-4,8-bis(1,1-dimethylethyl)-2,10-dimethoxydibenzo d,f!1,3,2!-dioxaphosphepin-6-yl!oxy!-3,3'-bis(1,1-dimethylethyl)-5,5'-dimethoxy1,1'- biphenyl!-2-yl bis(4-hexylphenyl)ester of phosphorous acid havingthe formula: ##STR24## 2- 2- 4,8, -bis(1,1-dimethylethyl),2,10-dimethoxydibenzo- d,f!1,3,2!dioxophosphepin-6-yl!oxy!-3-(1,1-dimethylethyl)-5-methoxyphenyl!methyl!-4-methoxy,6-(1,1-dimethylethyl)phenyl diphenyl ester of phosphorous acid havingthe formula: ##STR25## 3-methoxy-1,3-cyclohexamethylene tetrakis3,6-bis(1,1-dimethylethyl)-2-naphthalenyl!ester of phosphorous acidhaving the formula: ##STR26## 2,5-bis(1,1-dimethylethyl)-1,4-phenylenetetrakis 2,4-bis(1,1-dimethylethyl)phenyl!ester of phosphorous acidhaving the formula: ##STR27## methylenedi-2,1-phenylene tetrakis2,4-bis(1,1-dimethylethyl)phenyl!ester of phosphorous acid having theformula: ##STR28## 1,1'-biphenyl!-2,2'-diyl tetrakis2-(1,1-dimethylethyl)-4-methoxyphenyl!ester of phosphorous acid havingthe formula: ##STR29##

As noted above, the metal-organophosphite ligand complex catalystsemployable in this invention may be formed by methods known in the art.The metal-organophosphite ligand complex catalysts may be in homogeneousor heterogeneous form. For instance, preformed rhodiumhydrido-carbonyl-organophosphite ligand catalysts may be prepared andintroduced into the reaction mixture of a particular process. Morepreferably, the metal-organophosphite ligand complex catalysts can bederived from a rhodium catalyst precursor which may be introduced intothe reaction medium for in situ formation of the active catalyst. Forexample, rhodium catalyst precursors such as rhodium dicarbonylacetylacetonate, Rh₂ O₃, Rh₄ (CO)₁₂, Rh₆ (CO)₁₆, Rh(NO₃)₃ and the likemay be introduced into the reaction mixture along with theorganophosphite ligand for the in situ formation of the active catalyst.In a preferred embodiment of this invention, rhodium dicarbonylacetylacetonate is employed as a rhodium precursor and reacted in thepresence of a solvent with the organophosphite ligand to form acatalytic rhodium-organophosphite ligand complex precursor which isintroduced into the reaction zone along with excess (free)organophosphite ligand for the in situ formation of the active catalyst.In any event, it is sufficient for the purpose of this invention thatcarbon monoxide, hydrogen and organophosphite compound are all ligandsthat are capable of being complexed with the metal and that an activemetal-organophosphite ligand catalyst is present in the reaction mixtureunder the conditions used in the hydroformylation reaction.

More particularly, a catalyst precursor composition can be formedconsisting essentially of a solubilized metal-organophosphite ligandcomplex precursor catalyst, an organic solvent and free organophosphiteligand. Such precursor compositions may be prepared by forming asolution of a rhodium starting material, such as a rhodium oxide,hydride, carbonyl or salt, e.g., a nitrate, which may or may not be incomplex combination with a organophosphite ligand as defined herein. Anysuitable rhodium starting material may be employed, e.g. rhodiumdicarbonyl acetylacetonate, Rh₂ O₃, Rh₄ (CO)₁₂, Rh₆ (CO)₁₆, Rh(NO₃)₃,and organophosphite ligand rhodium carbonyl hydrides. Carbonyl andorganophosphite ligands, if not already complexed with the initialrhodium, may be complexed to the rhodium either prior to or in situduring the process.

By way of illustration, the preferred catalyst precursor composition ofthis invention consists essentially of a solubilized rhodium carbonylorganophosphite ligand complex precursor catalyst, a solvent andoptionally free organophosphite ligand prepared by forming a solution ofrhodium dicarbonyl acetylacetonate, an organic solvent and aorganophosphite ligand as defined herein. The organophosphite ligandreadily replaces one of the carbonyl ligands of the rhodiumacetylacetonate complex precursor at room temperature as witnessed bythe evolution of carbon monoxide gas. This substitution reaction may befacilitated by heating the solution if desired. Any suitable organicsolvent in which both the rhodium dicarbonyl acetylacetonate complexprecursor and rhodium organophosphite ligand complex precursor aresoluble can be employed. The amounts of rhodium complex catalystprecursor, organic solvent and organophosphite ligand, as well as theirpreferred embodiments present in such catalyst precursor compositionsmay obviously correspond to those amounts employable in the processes ofthis invention. Experience has shown that the acetylacetonate ligand ofthe precursor catalyst is replaced after the process, e.g.,hydroformylation, has begun with a different ligand, e.g., hydrogen,carbon monoxide or organophosphite ligand, to form the active complexcatalyst as explained above. The acetylacetone which is freed from theprecursor catalyst under hydroformylation conditions is removed from thereaction medium with the product aldehyde and thus is in no waydetrimental to the hydroformylation process. The use of such preferredrhodium complex catalytic precursor compositions provides a simpleeconomical and efficient method for handling the rhodium precursorrhodium and hydroformylation start-up.

Accordingly, the metal-organophosphite ligand complex catalysts used inthe processes of this invention consists essentially of the metalcomplexed with carbon monoxide, i.e., hydroformylation, and anorganophosphite ligand, said ligand being bonded (complexed) to themetal in a chelated and/or non-chelated fashion. Moreover, theterminology "consists essentially of", as used herein, does not exclude,but rather includes, hydrogen complexed with the metal, in addition tocarbon monoxide and the organophosphite ligand. Further, suchterminology does not exclude the possibility of other organic ligandsand/or anions that might also be complexed with the metal. Materials inamounts which unduly adversely poison or unduly deactivate the catalystare not desirable and so the catalyst most desirably is free ofcontaminants such as metal-bound halogen (e.g., chlorine, and the like)although such may not be absolutely necessary. The hydrogen and/orcarbonyl ligands of an active metal-organophosphite ligand complexcatalyst may be present as a result of being ligands bound to aprecursor catalyst and/or as a result of in situ formation, e.g., due tothe hydrogen and carbon monoxide gases employed in hydroformylationprocess of this invention.

As noted above, the organophosphite ligands can be employed as both theligand of the metal-organophosphite ligand complex catalyst, as well as,the free organophosphite ligand that can be present in the reactionmedium of the processes of this invention. In addition, it is to beunderstood that while the organophosphite ligand of themetal-organophosphite ligand complex catalyst and any excess freeorganophosphite ligand preferably present in a given process of thisinvention are normally the same type of ligand, different types oforganophosphite ligands, as well as, mixtures of two or more differentorganophosphite ligands may be employed for each purpose in any givenprocess, if desired.

The amount of metal-organophosphite ligand complex catalyst present inthe reaction medium of a given process of this invention need only bethat minimum amount necessary to provide the given metal concentrationdesired to be employed and which will furnish the basis for at leastthat catalytic amount of metal necessary to catalyze the particularprocess desired. In general, metal concentrations in the range of fromabout 1 part per million to about 10,000 parts per million, calculatedas free metal, and ligand to metal mole ratios in the catalyst solutionranging from about 1:1 or less to about 200:1 or greater, should besufficient for most processes.

As noted above, in addition to the metal-organophosphite ligand complexcatalysts, the processes of this invention and especially thehydroformylation process can be carried out in the presence of freeorganophosphite ligand. While the processes of this invention may becarried out in any excess amount of free organophosphite ligand desired,the employment of free organophosphite ligand may not be absolutelynecessary. Accordingly, in general, amounts of ligand of from about 1.1or less to about 100, or higher if desired, moles per mole of metal(e.g., rhodium) present in the reaction medium should be suitable formost purposes, particularly with regard to rhodium catalyzedhydroformylation; said amounts of ligand employed being the sum of boththe amount of ligand that is bound (complexed) to the metal present andthe amount of free (non-complexed) ligand present. Of course, ifdesired, make-up ligand can be supplied to the reaction medium of theprocess, at any time and in any suitable manner, to maintain apredetermined level of free ligand in the reaction medium.

As indicated above, the catalysts may be in heterogeneous form duringthe reaction and/or during the product separation. Such catalysts areparticularly advantageous in the hydroformylation of olefins to producehigh boiling or thermally sensitive aldehydes, so that the catalyst maybe separated from the products by filtration or decantation at lowtemperatures. For example, the rhodium catalyst may be attached to asupport so that the catalyst retains its solid form during both thehydroformylation and separation stages, or is soluble in a liquidreaction medium at high temperatures and then is precipitated oncooling.

As an illustration, the rhodium catalyst may be impregnated onto anysolid support, such as inorganic oxides, (i.e. alumina, silica, titania,or zirconia) carbon, or ion exchange resins. The catalyst may besupported on, or intercalated inside the pores of, a zeolite, glass orclay; the catalyst may also be dissolved in a liquid film coating thepores of said zeolite or glass. Such zeolite-supported catalysts areparticularly advantageous for producing one or more regioisomericaldehydes in high selectivity, as determined by the pore size of thezeolite. The techniques for supporting catalysts on solids, such asincipient wetness, which will be known to those skilled in the art. Thesolid catalyst thus formed may still be complexed with one or more ofthe ligands defined above. Descriptions of such solid catalysts may befound in for example: J. Mol. Cat. 1991, 70, 363-368; Catal. Lett. 1991,8, 209-214; J. Organomet. Chem, 1991, 403, 221-227; Nature, 1989, 339,454-455; J. Catal. 1985, 96, 563-573; J. Mol. Cat. 1987, 39, 243-259.

The metal, e.g., rhodium, catalyst may be attached to a thin film ormembrane support, such as cellulose acetate or polyphenylenesulfone, asdescribed in for example J. Mol. Cat. 1990, 63, 213-221.

The metal, e.g., rhodium, catalyst may be attached to an insolublepolymeric support through an organophosphorus-containing ligand, such asa phosphite, incorporated into the polymer. The supported catalyst isnot limited by the choice of polymer or phosphorus-containing speciesincorporated into it. Descriptions of polymer-supported catalysts may befound in for example: J. Mol. Cat. 1993, 83, 17-35; Chemtech 1983, 46;J. Am. Chem. Soc. 1987, 109, 7122-7127.

In the heterogeneous catalysts described above, the catalyst may remainin its heterogeneous form during the entire process and catalystseparation process. In another embodiment of the invention, the catalystmay be supported on a polymer which, by the nature of its molecularweight, is soluble in the reaction medium at elevated temperatures, butprecipitates upon cooling, thus facilitating catalyst separation fromthe reaction mixture. Such "soluble" polymer-supported catalysts aredescribed in for example: Polymer, 1992, 33, 161; J. Org. Chem. 1989,54, 2726-2730.

More preferably, the hydroformylation reaction is carried out in theslurry phase due to the high boiling points of the products, and toavoid decomposition of the aldehyde products. The catalyst may then beseparated from the product mixture, for example, by filtration ordecantation. The reaction product fluid may contain a heterogeneousmetal-organophosphite ligand complex catalyst, e.g., slurry, or at leasta portion of the reaction product fluid may contact a fixedheterogeneous metal-organophosphite ligand complex catalyst during theparticular process. In an embodiment of this invention, themetal-organophosphite ligand complex catalyst may be slurried in thereaction product fluid.

The permissible reaction conditions employable in the processes of thisinvention are, of course, chosen depending on the particular synthesesdesired. Such process conditions are well known in the art. All of theprocesses of this invention can be carried out in accordance withconventional procedures known in the art. Illustrative reactionconditions for conducting the processes of this invention are described,for example, in Kirk-Othmer, Encyclopedia of Chemical Technology, FourthEdition, 1996, the pertinent portions of which are incorporated hereinby reference. Depending on the particular process, operatingtemperatures may range from about -80° C. or less to about 500° C. orgreater and operating pressures can range from about 1 psig or less toabout 10,000 psig or greater.

The processes of this invention are conducted for a period of timesufficient to produce the desired products. The exact reaction timeemployed is dependent, in part, upon factors such as temperature,pressure, nature and proportion of starting materials, and the like. Thereaction time will normally be within the range of from about one-halfto about 200 hours or more, and preferably from less than about one toabout 10 hours.

The processes of this invention and preferably the hydroformylationprocess may be conducted in the presence of an organic solvent for themetal-organophosphite ligand complex catalyst. The solvent may alsocontain dissolved water up to the saturation limit. Depending on theparticular catalyst and reactants employed, suitable organic solventsinclude, for example, alcohols, alkanes, alkenes, alkynes, ethers,aldehydes, ketones, esters, amides, amines, aromatics and the like. Anysuitable solvent which does not unduly adversely interfere with theintended processes can be employed and such solvents may include thoseheretofore commonly employed in known metal catalyzed processes.Increasing the dielectric constant or polarity of a solvent maygenerally tend to favor increased reaction rates. Of course, mixtures ofone or more different solvents may be employed if desired. It is obviousthat the amount of solvent employed is not critical to the subjectinvention and need only be that amount sufficient to provide thereaction medium with the particular metal concentration desired for agiven process. In general, the amount of solvent when employed may rangefrom about 5 percent by weight up to about 99 percent by weight or morebased on the total weight of the reaction mixture starting materials.

The processes of this invention are useful for preparing substituted andunsubstituted optically active and non-optically active compounds.Illustrative compounds prepared by the processes of this inventioninclude, for example, substituted and unsubstituted alcohols or phenols;amines; amides; ethers or epoxides; esters; ketones; aldehydes; andnitrites. Illustrative of suitable optically active and non-opticallyactive compounds which can be prepared by the processes of thisinvention (including starting material compounds as describedhereinabove) include those permissible compounds which are described inKirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, 1996,the pertinent portions of which are incorporated herein by reference,and The Merck Index, An Encyclopedia of Chemicals, Drugs andBiologicals, Eleventh Edition, 1989, the pertinent portions of which areincorporated herein by reference.

The desired products of this invention may be recovered in anyconventional manner and one or more separators or separation zones maybe employed in any given process to recover the desired reaction productfrom its crude reaction product fluid. Suitable separation methodsinclude, for example, solvent extraction, crystallization, distillation,vaporization, wiped film evaporation, falling film evaporation and thelike. It may be desired to remove the products from the crude reactionmixture as they are formed through the use of trapping agents asdescribed in published Patent Cooperation Treaty Patent Application WO88/08835. A preferred method for separating the product mixtures fromthe other components of the crude reaction mixtures is by membraneseparation. Such membrane separation can be achieved as set out in U.S.Pat. No. 5,430,194 and copending U.S. patent application Ser. No.08/430,790, filed May 5, 1995, referred to above.

The processes of this invention may be carried out using, for example, afixed bed reactor, a fluid bed reactor, a continuous stirred tankreactor (CSTR) or a slurry reactor. The optimum size and shape of thecatalysts will depend on the type of reactor used. In general, for fluidbed reactors, a small, spherical, catalyst particle is preferred foreasy fluidization. With fixed bed reactors, larger catalyst particlesare preferred so the back pressure within the reactor is kept reasonablylow. The at least one reaction zone employed in this invention may be asingle vessel or may comprise two or more discrete vessels. The at leastone separation zone employed in this invention may be a single vessel ormay comprise two or more discrete vessels. The at least one scrubberzone employed in this invention may be a single vessel or may comprisetwo or more discrete vessels. It should be understood that the reactionzone(s) and separation zone(s) employed herein may exist in the samevessel or in different vessels. For example, reactive separationtechniques such as reactive distillation, reactive membrane separationand the like may occur in the reaction zone(s).

The processes of this invention can be conducted in a batch orcontinuous fashion, with recycle of unconsumed starting materials ifrequired. The reaction can be conducted in a single reaction zone or ina plurality of reaction zones, in series or in parallel or it may beconducted batchwise or continuously in an elongated tubular zone orseries of such zones. The materials of construction employed should beinert to the starting materials during the reaction and the fabricationof the equipment should be able to withstand the reaction temperaturesand pressures. Means to introduce and/or adjust the quantity of startingmaterials or ingredients introduced batchwise or continuously into thereaction zone during the course of the reaction can be convenientlyutilized in the processes especially to maintain the desired molar ratioof the starting materials. The reaction steps may be effected by theincremental addition of one of the starting materials to the other.Also, the reaction steps can be combined by the joint addition of thestarting materials. When complete conversion is not desired or notobtainable, the starting materials can be separated from the product,for example by distillation, and the starting materials then recycledback into the reaction zone.

The processes may be conducted in either glass lined, stainless steel orsimilar type reaction equipment. The reaction zone may be fitted withone or more internal and/or external heat exchanger(s) in order tocontrol undue temperature fluctuations, or to prevent any possible"runaway" reaction temperatures.

The processes of this invention may be conducted in one or more steps orstages. The exact number of reaction steps or stages will be governed bythe best compromise between capital costs and achieving high catalystselectivity, activity, lifetime and ease of operability, as well as theintrinsic reactivity of the starting materials in question and thestability of the starting materials and the desired reaction product tothe reaction conditions.

In an embodiment, the hydroforrylation processes useful in thisinvention may be carried out in a multistaged reactor such as described,for example, in copending U.S. patent application Ser. No. 08/757,743,filed on an even date herewith, the disclosure of which is incorporatedherein by reference. Such multistaged reactors can be designed withinternal, physical barriers that create more than one theoreticalreactive stage per vessel. In effect, it is like having a number ofreactors inside a single continuous stirred tank reactor vessel.Multiple reactive stages within a single vessel is a cost effective wayof using the reactor vessel volume. It significantly reduces the numberof vessels that otherwise would be required to achieve the same results.Fewer vessels reduces the overall capital required and maintenanceconcerns with separate vessels and agitators.

Hydroformylation Processes

A preferred process useful in this invention is hydroformylation.Illustrative metal-organophosphite ligand complex catalyzedhydroformylation processes which may experience such hydrolyticdegradation of the organophosphite ligand and catalytic deactivationinclude such processes as described, for example, in U.S. Pat. Nos.4,148,830; 4,593,127; 4,769,498; 4,717,775; 4,774,361; 4,885,401;5,264,616; 5,288,918; 5,360,938; 5,364,950; and 5,491,266; thedisclosures of which are incorporated herein by reference. Accordingly,the hydroformylation processing techniques of this invention maycorrespond to any known processing techniques. Preferred process arethose involving catalyst liquid recycle hydroformylation processes.

In general, such catalyst liquid recycle hydroformylation processesinvolve the production of aldehydes by reacting an olefinic unsaturatedcompound with carbon monoxide and hydrogen in the presence of ametal-organophosphite ligand complex catalyst in a liquid medium thatalso contains an organic solvent for the catalyst and ligand. Preferablyfree organophosphite ligand is also present in the liquidhydroformylation reaction medium. The recycle procedure generallyinvolves withdrawing a portion of the liquid reaction medium containingthe catalyst and aldehyde product from the hydroformylation reactor(i.e., reaction zone), either continuously or intermittently, andrecovering the aldehyde product therefrom by use of a composite membranesuch as disclosed in U.S. Pat. No. 5,430,194 and copending U.S. patentapplication Ser. No. 08/430,790, filed May 5,1995, the disclosures ofwhich are incorporated herein by reference, or by the more conventionaland preferred method of distilling it (i.e., vaporization separation) inone or more stages under normal, reduced or elevated pressure, asappropriate, in a separate distillation zone, the non-volatilized metalcatalyst containing residue being recycled to the reaction zone asdisclosed, for example, in U.S. Pat. No. 5,288,918. Condensation of thevolatilized materials, and separation and further recovery thereof,e.g., by further distillation, can be carried out in any conventionalmanner, the crude aldehyde product can be passed on for furtherpurification and isomer separation, if desired, and any recoveredreactants, e.g., olefinic starting material and syn gas, can be recycledin any desired manner to the hydroformylation zone (reactor). Therecovered metal catalyst containing raffinate of such membraneseparation or recovered non-volatilized metal catalyst containingresidue of such vaporization separation can be recycled, to thehydroformylation zone (reactor) in any conventional manner desired.

In a preferred embodiment, the hydroformylation reaction product fluidsemployable herein includes any fluid derived from any correspondinghydroformylation process that contains at least some amount of fourdifferent main ingredients or components, i.e., the aldehyde product, ametal-organophosphite ligand complex catalyst, free organophosphiteligand and an organic solubilizing agent for said catalyst and said freeligand, said ingredients corresponding to those employed and/or producedby the hydroformylation process from whence the hydroformylationreaction mixture starting material may be derived. It is to beunderstood that the hydroformylation reaction mixture compositionsemployable herein can and normally will contain minor amounts ofadditional ingredients such as those which have either been deliberatelyemployed in the hydroformylation process or formed in situ during saidprocess. Examples of such ingredients that can also be present includeunreacted olefin starting material, carbon monoxide and hydrogen gases,and in situ formed type products, such as saturated hydrocarbons and/orunreacted isomerized olefins corresponding to the olefin startingmaterials, and high boiling liquid aldehyde condensation byproducts, aswell as other inert co-solvent type materials or hydrocarbon additives,if employed.

The substituted or unsubstituted olefin reactants that may be employedin the hydroformylation processes (and other suitable processes) of thisinvention include both optically active (prochiral and chiral) andnon-optically active (achiral) olefinic unsaturated compounds containingfrom 2 to 40, preferably 4 to 20, carbon atoms. Such olefinicunsaturated compounds can be terminally or internally unsaturated and beof straight-chain, branched chain or cyclic structures, as well asolefin mixtures, such as obtained from the oligomerization of propene,butene, isobutene, etc. (such as so called dimeric, trimeric ortetrameric propylene and the like, as disclosed, for example, in U.S.Pat. Nos. 4,518,809 and 4,528,403). Moreover, such olefin compounds mayfurther contain one or more ethylenic unsaturated groups, and of course,mixtures of two or more different olefinic unsaturated compounds may beemployed as the starting material if desired. For example, commercialalpha olefins containing four or more carbon atoms may contain minoramounts of corresponding internal olefins and/or their correspondingsaturated hydrocarbon and that such commercial olefins need notnecessarily be purified from same prior to being reacted. Illustrativemixtures of olefinic starting materials that can be employed in thehydroformylation reactions include, for example, mixed butenes, e.g.,Raffinate I and II. Further such olefinic unsaturated compounds and thecorresponding products derived therefrom may also contain one or moregroups or substituents which do not unduly adversely affect theprocesses of this invention such as described, for example, in U.S. Pat.Nos. 3,527,809, 4,769,498 and the like.

Most preferably the subject invention is especially useful for theproduction of non-optically active aldehydes, by hydroformylatingachiral alpha-olefins containing from 2 to 30, preferably 4 to 20,carbon atoms, and achiral internal olefins containing from 4 to 20carbon atoms as well as starting material mixtures of such alpha olefinsand internal olefins.

Illustrative alpha and internal olefins include, for example, ethylene,propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene,1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene,1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene,2-butene, 2-methyl propene (isobutylene), 2-methylbutene, 2-pentene,2-hexene, 3-hexane, 2-heptene, 2-octene, cyclohexene, propylene dimers,propylene trimers, propylene tetramers, butadiene, piperylene, isoprene,2-ethyl-1-hexene, styrene, 4-methyl styrene, 4-isopropyl styrene,4-tert-butyl styrene, alpha-methyl styrene, 4-tert-butyl-alpha-methylstyrene, 1,3-diisopropenylbenzene, 3-phenyl-1-propene, 1,4-hexadiene,1,7-octadiene, 3-cyclohexyl-1-butene, and the like, as well as,1,3-dienes, butadiene, alkyl alkenoates, e.g., methyl pentenoate,alkenyl alkanoates, alkenyl alkyl ethers, alkenols, e.g., pentenols,alkenals, e.g., pentenals, and the like, such as allyl alcohol, allylbutyrate, hex-1-en-4-ol, oct-1-en-4-ol, vinyl acetate, allyl acetate,3-butenyl acetate, vinyl propionate, allyl propionate, methylmethacrylate, vinyl ethyl ether, vinyl methyl ether, allyl ethyl ether,n-propyl-7-octenoate, 3-butenenitrile, 5-hexenamide, eugenol,iso-eugenol, safrole, iso-safrole, anethol, 4-allylanisole, indene,limonene, beta-pinene, dicyclopentadiene, cyclooctadiene, camphene,linalool, and the like.

Illustrative prochiral and chiral olefins useful in the asymmetrichydroformylation processes (and other asymmetric processes) that can beemployed to produce enantiomeric product mixtures that may beencompassed by in this invention include those represented by theformula: ##STR30## wherein R₁, R₂, R₃ and R₄ are the same or different(provided R₁ is different from R₂ or R₃ is different from R₄) and areselected from hydrogen; alkyl; substituted alkyl, said substitutionbeing selected from dialkylamino such as benzylamino and dibenzylamino,alkoxy such as methoxy and ethoxy, acyloxy such as acetoxy, halo, nitro,nitrile, thio, carbonyl, carboxamide, carboxaldehyde, carboxyl,carboxylic ester; aryl including phenyl; substituted aryl includingphenyl, said substitution being selected from alkyl, amino includingalkylamino and dialkylamino such as benzylamino and dibenzylamino,hydroxy, alkoxy such as methoxy and ethoxy, acyloxy such as acetoxy,halo, nitrile, nitro, carboxyl, carboxaldehyde, carboxylic ester,carbonyl, and thio; acyloxy such as acetoxy; alkoxy such as methoxy andethoxy; amino including alkylamino and dialkylamino such as benzylaminoand dibenzylamino; acylamino and diacylamino such as acetylbenzylaminoand diacetylamino; nitro; carbonyl; nitrile; carboxyl; carboxamide;carboxaldehyde; carboxylic ester; and alkylmercapto such asmethylmercapto. It is understood that the prochiral and chiral olefinsof this definition also include molecules of the above general formulawhere the R groups are connected to form ring compounds, e.g.,3-methyl-1-cyclohexene, and the like.

Illustrative optically active or prochiral olefinic compounds useful inasymmetric hydroformylation processes (and other asymmetric processes)of this invention include, for example, p-isobutylstyrene,2-vinyl-6-methoxy-2-naphthylene, 3-ethenylphenyl phenyl ketone,4-ethenylphenyl-2-thienylketone, 4-ethenyl-2-fluorobiphenyl,4-(1,3-dihydro- 1-oxo-2H-isoindol-2-yl)styrene,2-ethenyl-5-benzoylthiophene, 3-ethenylphenyl phenyl ether,propenylbenzene, isobutyl-4-propenylbenzene, phenyl vinyl ether and thelike. Other olefinic compounds include substituted aryl ethylenes asdescribed, for example, in U.S. Pat. Nos. 4,329,507, 5,360,938 and5,491,266, the disclosures of which are incorporated herein byreference.

Illustrative of suitable substituted and unsubstituted olefinic startingmaterials include those permissible substituted and unsubstitutedolefinic compounds described in Kirk-Othmer, Encyclopedia of ChemicalTechnology, Fourth Edition, 1996, the pertinent portions of which areincorporated herein by reference.

As noted, the hydroformylation processes of this invention involve theuse of a metal-organophosphite ligand complex catalyst as describedhereinabove. The hydroformylation catalysts may be in homogeneous orheterogeneous form during the reaction and/or during the productseparation. Of course mixtures of such catalysts can also be employed ifdesired. The amount of metal-organophosphite ligand complex catalystpresent in the reaction medium of a given hydroformylation processencompassed by this invention need only be that minimum amount necessaryto provide the given metal concentration desired to be employed andwhich will furnish the basis for at least the catalytic amount of metalnecessary to catalyze the particular hydroformylation process involvedsuch as disclosed, for example, in the above-mentioned patents. Ingeneral, metal, e.g., rhodium, concentrations in the range of from about10 parts per million to about 1000 parts per million, calculated as freerhodium, in the hydroformylation reaction medium should be sufficientfor most processes, while it is generally preferred to employ from about10 to 500 parts per million of metal, e.g., rhodium, and more preferablyfrom 25 to 350 parts per million of metal, e.g., rhodium.

In addition to the metal-organophosphite ligand complex catalyst, freeorganophosphite ligand (i.e., ligand that is not complexed with themetal) may also be present in the hydroformylation reaction medium. Thefree organophosphite ligand may correspond to any of the above-definedorganophosphite ligands employable herein. It is preferred that the freeorganophosphite ligand be the same as the organophosphite ligand of themetal-organophosphite ligand complex catalyst employed. However, suchligands need not be the same in any given process. The hydroformylationprocess of this invention may involve from about 0.1 moles or less toabout 100 moles or higher, of free organophosphite ligand per mole ofmetal in the hydroformylation reaction medium. Preferably thehydroformylation process of this invention is carried out in thepresence of from about 1 to about 50 moles of organophosphite ligand,and more preferably for organopolyphosphites from about 1.1 to about 4moles of organopolyphosphite ligand, per mole of metal present in thereaction medium; said amounts of organophosphite ligand being the sum ofboth the amount of organophosphite ligand that is bound (complexed) tothe metal present and the amount of free (non-complexed) organophosphiteligand present. Since it is more preferred to produce non-opticallyactive aldehydes by hydroformylating achiral olefins, the more preferredorganophosphite ligands are achiral type organophosphite ligands,especially those encompassed by Formula (V) above, and more preferablythose of Formulas (VI) and (IX) above. Of course, if desired, make-up oradditional organophosphite ligand can be supplied to the reaction mediumof the hydroformylaticLn process at any time and in any suitable manner,e.g. to maintain a predetermined level of free ligand in the reactionmedium.

The reaction conditions of the hydroformylation processes encompassed bythis invention may include any suitable type hydroformylation conditionsheretofore employed for producing optically active and/or non-opticallyactive aldehydes. For instance, the total gas pressure of hydrogen,carbon monoxide and olefin starting compound of the hydroformylationprocess may range from about 1 to about 10,000 psia. In general,however, it is preferred that the process be operated at a total gaspressure of hydrogen, carbon monoxide and olefin starting compound ofless than about 2000 psia and more preferably less than about 500 psia.The minimum total pressure is limited predominately by the amount ofreactants necessary to obtain a desired rate of reaction. Morespecifically the carbon monoxide partial pressure of thehydroformylation process of this invention is preferable from about 1 toabout 1000 psia, and more preferably from about 3 to about 800 psia,while the hydrogen partial pressure is preferably about 5 to about 500psia and more preferably from about 10 to about 300 psia. In general H₂:CO molar ratio of gaseous hydrogen to carbon monoxide may range fromabout 1:10 to 100:1 or higher, the more preferred hydrogen to carbonmonoxide molar ratio being from about 1:10 to about 10:1. Further, thehydroformylation process may be conducted at a reaction temperature fromabout -25° C. to about 200° C. In general hydroformylation reactiontemperatures of about 50° C. to about 120° C. are preferred for alltypes of olefinic starting materials. Of course it is to be understoodthat when non-optically active aldehyde products are desired, achiraltype olefin starting materials and organophosphite ligands are employedand when optically active aldehyde products are desired prochiral orchiral type olefin starting materials and organophosphite ligands areemployed. Of course, it is to be also understood that thehydroformylation reaction conditions employed will be governed by thetype of aldehyde product desired.

The hydroformylation processes encompassed by this invention are alsoconducted in the presence of an organic solvent for themetal-organophosphite ligand complex catalyst and free organophosphiteligand. The solvent may also contain dissolved water up to thesaturation limit. Depending on the particular catalyst and reactantsemployed, suitable organic solvents include, for example, alcohols,alkanes, alkenes, alkynes, ethers, aldehydes, higher boiling aldehydecondensation byproducts, ketones, esters, amides, tertiary amines,aromatics and the like. Any suitable solvent which does not undulyadversely interfere with the intended hydroformylation reaction can beemployed and such solvents may include those disclosed heretoforecommonly employed in known metal catalyzed hydroformylation reactions.Mixtures of one or more different solvents may be employed if desired.In general, with regard to the production of achiral (non-opticallyactive) aldehydes, it is preferred to employ aldehyde compoundscorresponding to the aldehyde products desired to be produced and/orhigher boiling aldehyde liquid condensation byproducts as the mainorganic solvents as is common in the art. Such aldehyde condensationbyproducts can also be preformed if desired and used accordingly.Illustrative preferred solvents employable in the production ofaldehydes include ketones (e.g. acetone and methylethyl ketone), esters(e.g. ethyl acetate), hydrocarbons (e.g. toluene), nitrohydrocarbons(e.g. nitrobenzene), ethers (e.g. tetrahydrofuran (THF) and sulfolane.Suitable solvents are disclosed in U.S. Pat. No. 5,312,996. The amountof solvent employed is not critical to the subject invention and needonly be that amount sufficient to solubilize the catalyst and freeligand of the hydroformylation reaction mixture to be treated. Ingeneral, the amount of solvent may range from about 5 percent by weightup to about 99 percent by weight or more based on the total weight ofthe hydroformylation reaction mixture starting material.

Accordingly illustrative non-optically active aldehyde products includee.g., propionaldehyde, n-butyraldehyde, isobutyraldehyde,n-valeraldehyde, 2-methyl 1-butyraldehyde, hexanal, hydroxyhexanal,2-methyl valeraldehyde, heptanal, 2-methyl 1-hexanal, octanal, 2-methyl1-heptanal, nonanal, 2-methyl-1-octanal, 2-ethyl 1-heptanal, 3-propyl1-hexanal, decanal, adipaldehyde, 2-methylglutaraldehyde,2-methyladipaldehyde, 3-methyladipaldehyde, 3-hydroxypropionaldehyde,6-hydroxyhexanal, alkenals, e.g., 2-, 3- and 4-pentenal, alkyl5-formylvalerate, 2-methyl-1-nonanal, undecanal, 2-methyl 1-decanal,dodecanal, 2-methyl 1-undecanal, tridecanal, 2-methyl 1-tridecanal,2-ethyl, 1-dodecanal, 3-propyl-1-undecanal, pentadecanal,2-methyl-1-tetradecanal, hexadecanal, 2-methyl-1-pentadecanal,heptadecanal, 2-methyl-1-hexadecanal, octadecanal, 2-methyl-1-heptadecanal, nonodecanal, 2-methyl- 1-octadecanal, 2-ethyl1-heptadecanal, 3-propyl-1-hexadecanal, eicosanal,2-methyl-1-nonadecanal, heneicosanal, 2-methyl-1-eicosanal, tricosanal,2-methyl-1-docosanal, tetracosanal, 2-methyl-1-tricosanal, pentacosanal,2-methyl- 1-tetracosanal, 2-ethyl 1-tricosanal, 3-propyl-1-docosanal,heptacosanal, 2-methyl-1-octacosanal, nonacosanal,2-methyl-1-octacosanal, hentriacontanal, 2-methyl-1-triacontanal, andthe like.

Illustrative optically active aldehyde products include (enantiomeric)aldehyde compounds prepared by the asymmetric hydroformylation processof this invention such as, e.g. S-2-(p-isobutylphenyl)-propionaldehyde,S-2-(6-methoxy-2-naphthyl)propionaldehyde,S-2-(3-benzoylphenyl)-propionaldehyde,S-2-(p-thienoylphenyl)propionaldehyde,S-2-(3-fluoro-4-phenyl)phenylpropionaldehyde, S-2-4-(1,3-dihydro-1-oxo-2H-isoindol-2-yl)phenyl!propionaldehyde,S-2-(2-methylacetaldehyde)-5-benzoylthiophene and the like.

Illustrative of suitable substituted and unsubstituted aldehyde productsinclude those permissible substituted and unsubstituted aldehydecompounds described in Kirk-Othmer, Encyclopedia of Chemical Technology,Fourth Edition, 1996, the pertinent portions of which are incorporatedherein by reference.

As indicated above, it is generally preferred to carry out thehydroformylation processes of this invention in a continuous manner. Ingeneral, continuous hydroformylation processes are well known in the artand may involve: (a) hydroformylating the olefinic starting material(s)with carbon monoxide and hydrogen in a liquid homogeneous reactionmixture comprising a solvent, the metal-organophosphite ligand complexcatalyst, and free organophosphite ligand; (b) maintaining reactiontemperature and pressure conditions favorable to the hydroformylation ofthe olefinic starting material(s); (c) supplying make-up quantities ofthe olefinic starting material(s), carbon monoxide and hydrogen to thereaction medium as those reactants are used up; and (d) recovering thedesired aldehyde hydroformylation product(s) in any manner desired. Thecontinuous process can be carried out in a single pass mode, i.e.,wherein a vaporous mixture comprising unreacted olefinic startingmaterial(s) and vaporized aldehyde product is removed from the liquidreaction mixture from whence the aldehyde product is recovered andmake-up olefinic starting material(s), carbon monoxide and hydrogen aresupplied to the liquid reaction medium for the next single pass withoutrecycling the unreacted olefinic starting material(s). Such types ofrecycle procedure are well known in the art and may involve the liquidrecycling of the metal-organophosphite complex catalyst fluid separatedfrom the desired aldehyde reaction product(s), such as disclosed, forexample, in U.S. Pat. No. 4,148,830 or a gas recycle procedure such asdisclosed, for example, in U.S. Pat. No. 4,247,486, as well as acombination of both a liquid and gas recycle procedure if desired. Thedisclosures of said U.S. Pat. Nos. 4,148,830 and 4,247,486 areincorporated herein by reference thereto. The most preferredhydroformylation process of this invention comprises a continuous liquidcatalyst recycle process. Suitable liquid catalyst recycle proceduresare disclosed, for example, in U.S. Pat. Nos. 4,668,651; 4,774,361;5,102,505 and 5,110,990.

In an embodiment of this invention, the aldehyde product mixtures may beseparated from the other components of the crude reaction mixtures inwhich the aldehyde mixtures are produced by any suitable method.Suitable separation methods include, for example, solvent extraction,phase separation, crystallization, distillation, vaporization, wipedfilm evaporation, falling film evaporation and the like. It may bedesired to remove the aldehyde products from the crude reaction mixtureas they are formed through the use of trapping agents as described inpublished Patent Cooperation Treaty Patent Application WO 88/08835. Apreferred method for separating the aldehyde mixtures from the othercomponents of the crude reaction mixtures is by membrane separation.Such membrane separation can be achieved as set out in U.S. Pat. No.5,430,194 and copending U.S. patent application Ser. No. 08/430,790,filed May 5, 1995, referred to above.

As indicated above, at the conclusion of (or during) the process of thisinvention, the desired aldehydes may be recovered from the reactionmixtures used in the process of this invention. For example, therecovery techniques disclosed in U.S. Pat. Nos. 4,148,830 and 4,247,486can be used. For instance, in a continuous liquid catalyst recycleprocess the portion of the liquid reaction mixture (containing aldehydeproduct, catalyst, etc.), i.e., reaction product fluid, removed from thereaction zone can be passed to a separation zone, e.g.,vaporizer/separator, wherein the desired aldehyde product can beseparated via distillation, in one or more stages, under normal, reducedor elevated pressure, from the liquid reaction fluid, condensed andcollected in a product receiver, and further purified if desired. Theremaining non-volatilized catalyst containing liquid reaction mixturemay then be recycled back to the reaction zone as may if desired anyother volatile materials, e.g., unreacted olefin, together with anyhydrogen and carbon monoxide dissolved in the liquid reaction afterseparation thereof from the condensed aldehyde product, e.g., bydistillation in any conventional manner. In general, it is preferred toseparate the desired aldehydes from the catalyst-containing reactionmixture under reduced pressure and at low temperatures so as to avoidpossible degradation of the organophosphite ligand and reactionproducts. When an alpha-mono-olefin reactant is also employed, thealdehyde derivative thereof can also be separated by the above methods.

More particularly, distillation and separation of the desired aldehydeproduct from the metal-organophosphite complex catalyst containingreaction product fluid may take place at any suitable temperaturedesired. In general, it is recommended that such distillation take placeat relatively low temperatures, such as below 150° C., and morepreferably at a temperature in the range of from about 50° C. to about140° C. It is also generally recommended that such aldehyde distillationtake place under reduced pressure, e.g., a total gas pressure that issubstantially lower than the total gas pressure employed duringhydroformylation when low boiling aldehydes (e.g., C₄ to C₆) areinvolved or under vacuum when high boiling aldehydes (e.g. C₇ orgreater) are involved. For instance, a common practice is to subject theliquid reaction product medium removed from the hydroformylationreaction zone to a pressure reduction so as to volatilize a substantialportion of the unreacted gases dissolved in the liquid medium which nowcontains a much lower synthesis gas concentration than was present inthe hydroformylation reaction medium to the distillation zone, e.g.vaporizer/separator, wherein the desired aldehyde product is distilled.In general, distillation pressures ranging from vacuum pressures on upto total gas pressure of about 50 psig should be sufficient for mostpurposes.

WATER TREATMENT

As stated above, the subject invention resides in the discovery thathydrolytic decomposition and metal catalyst deactivation as discussedherein can be prevented or lessened by treating at least a portion ofthe reaction product fluid derived from the processes of this inventionand which also contains phosphorus acidic compounds formed during theprocesses with water sufficient to remove at least some amount of thephosphorus acidic compounds from the reaction product fluid. Althoughboth water and acid are factors in the hydrolysis of organophosphiteligands, it has been surprisingly discovered that reaction systems,e.g., hydroformylation, are more tolerant of higher levels of water thanhigher levels of acid. Thus, the water can surprisingly be used toremove acid and decrease the rate of loss of organophosphite ligand byhydrolysis. The use of water to prevent and/or lessen hydrolyticdegradation of an organophosphite ligand and deactivation of ametal-organophosphite ligand complex catalyst in hydroformylationprocesses is disclosed in copending U.S. patent application Ser. No.08/753,504, filed on an even date herewith, the disclosure of which isincorporated herein by reference.

The removal of at least some amount of the phosphorus acid compounds,for example, H₃ PO₃, aldehyde acids such as hydroxy alkyl phosphonicacids, H₃ PO₄ and the like, from the hydroformylation system allows oneto control the acidity of the hydroformylation reaction medium, therebystabilizing the useful organophosphite ligand by preventing or lesseningits hydrolytic decomposition. The need to control the acidity inorganophosphite promoted metal catalyzed hydroformylation was explainedabove. Thus the purpose of the subject invention is to remove or reduceexcessive acidity from the catalyst system in order to maintain a properacidity level in the reaction product fluid so that the consumption ofthe useful organophosphite ligands do not hydrolytically degrade at anunacceptable rate while keeping catalyst activity at a productive level.The subject invention submits that the best means for regulating suchacidity is to extract (remove) such phosphorus acidic materials from thereaction product fluid using water. In this way the acidic materials areextracted into the water as disclosed herein as opposed to merely beingscavenged and/or neutralized and allowed to remain in the reactionmedium, thereby avoiding accumulation of such scavenged and/orneutralized byproducts, and preventing further possible necessarysecondary chemistry or the buildup of salt deposits in the reactionzone, separation zone and/or scrubber zone.

Said treatment of the metal-organophosphite ligand complex catalystcontaining reaction product fluid with water may be conducted in anysuitable manner or fashion desired that does not unduly adversely affectthe basic hydroformylation process from which said reaction productfluid was derived. For instance, the water treatment may be conducted onall or any portion of the desired reaction product fluid that is to betreated and which has been removed from the at least one reaction zoneor the at least one separation zone into at least one scrubber zone. Thetreated reaction product fluid may then be returned to the at least onereaction zone or the at least one separation zone. Alternately, watermay be sprayed into or otherwise added to the at least one reaction zoneor the at least one separation zone to achieve acidity control. Thewater layer formed may then be separated, e.g., decanted, from thereaction product fluid.

This invention involving the use of water is especially adaptable foruse in continuous liquid catalyst recycle hydroformylation processesthat employ the invention of U.S. Pat. No. 5,288,918, which comprisescarrying out the process in the presence of a catalytically activeenhancing additive, said additive being selected from the classconsisting of added water, a weakly acidic compound (e.g., biphenol), orboth added water and a weakly acidic compound. The enhancing additive isemployed to help selectively hydrolyze and prevent the build-up of anundesirable monophosphite byproduct that can be formed during certainprocesses and which poisons the metal catalyst as explained therein.Nonetheless, it is to be understood that a preferred hydroformylationprocess of this invention, i.e., the embodiment comprising preventingand/or lessening hydrolytic degradation of the organophosphite ligandand deactivation of the metal-organophosphite ligand complex catalyst by(a) withdrawing from said at least one reaction zone or said at leastone separation zone at least a portion of said reaction product fluidderived from said process and which also contains phosphorus acidiccompounds formed during said process, (b) treating in at least onescrubber zone at least a portion of the withdrawn reaction product fluidderived from said process and which also contains phosphorus acidiccompounds formed during said process with water sufficient to remove atleast some amount of the phosphorus acidic compounds from said reactionproduct fluid, and (c) returning the treated reaction product fluid tosaid at least one reaction zone or said at least one separation zone, isstill considered to be essentially a "non-aqueous" process, which is tosay, any water present in the hydroformylation reaction medium is notpresent in an amount sufficient to cause either the hydroformylationreaction or said medium to be considered as encompassing a separateaqueous or water phase or layer in addition to an organic phase.

Also, it is to be understood that another preferred process of thisinvention, i.e., the embodiment comprising preventing and/or lesseninghydrolytic degradation of the organophosphite ligand and deactivation ofthe metal-organophosphite ligand complex catalyst by treating at least aportion of said reaction product fluid derived from said process andwhich also contains phosphorus acidic compounds formed during saidprocess by introducing water into said at least one reaction zone and/orsaid at least one separation zone sufficient to remove at least someamount of the phosphorus acidic compounds from said reaction productfluid, is considered to be a separate aqueous or water phase or layer inaddition to an organic phase.

Thus, for example, the water may be used to treat all or part of areaction product fluid of a continuous liquid catalyst recyclehydroformylation process that has been removed from the reaction zone atany time prior to or after separation of the aldehyde product therefrom.More preferably said water treatment involves treating all or part ofthe reaction product fluid obtained after distillation of as much of thealdehyde product desired, for example, prior to or during the recyclingof said reaction product fluid to the reaction zone. For instance, apreferred mode would be to continuously pass all or part (e.g. a slipstream) of the recycled reaction product fluid that is being recycled tothe reaction zone through a liquid extractor containing the water justbefore said catalyst containing residue is to re-enter the reactionzone.

Thus it is to be understood that the metal-organophosphite ligandcomplex catalyst containing reaction product fluid to be treated withwater may contain in addition to the catalyst complex and its organicsolvent, aldehyde product, free organophosphite ligand, unreactedolefin, and any other ingredient or additive consistent with thereaction medium of the hydroformylation process from which said reactionproduct fluids are derived.

Moreover, removal of the desired aldehyde product can causeconcentrations of the other ingredients of the reaction product fluidsto be increased proportionately. Thus for example, the organophosphiteligand concentration in the metal-organophosphite ligand complexcatalyst containing reaction product fluid to be treated by the water inaccordance with the processes of this invention may range from betweenabout 0.005 and 15 weight percent based on the total weight of thereaction product fluid. Preferably the ligand concentration is between0.01 and 10 weight percent, and more preferably is between about 0.05and 5 weight percent on that basis. Similarly, the concentration of themetal in the metal-organophosphite ligand complex reaction product fluidto be treated by the water in accordance with the processes of thisinvention may be as high as about 5000 parts per million by weight basedon the weight of the reaction product fluid. Preferably the metalconcentration is between about 50 and 2500 parts per million by weightbased on the weight of the reaction product fluid, and more preferablyis between about 70 and 2000 parts per million by weight based on theweight of the reaction product fluid.

The manner in which the metal-organophosphite ligand complex catalystcontaining reaction product fluid and water are contacted, as well assuch treatment conditions, as the amount of water, temperature, pressureand contact time are not narrowly critical and obviously need only besufficient to obtain the results desired. For instance, said treatmentmay be carried out in any suitable vessel or container, e.g. anyconventional liquid extractor, which provides a suitable means forthorough contact between the organic reaction product fluid and water,may be employed herein. In general it is preferred to pass the organicreaction product fluid through the water in a sieve tray extractorcolumn in a counter-current fashion. The amount of water employed by thesubject invention and time of contact with the reaction product fluidneed only be that which is sufficient to remove at least some amount ofthe phosphorus acidic compounds which cause hydrolytic degradation ofthe desirable organophosphite ligands. Preferably the amount of water issufficient to at least maintain the concentration of such acidiccompounds below the threshold level that causes rapid degradation of theorganophosphite ligand.

For instance, a preferred quantity of water is the quantity whichensures that any degradation of the organophosphite ligand proceeds bythe "non-catalytic mechanism" as described in "The Kinetic Rate Law forAutocatalytic Reactions" by Mata-Perez et al., Journal of ChemicalEducation, Vol. 64, No. 11, November 1987, pages 925 to 927, rather thanby the "catalytic mechanism" described in said article. Typicallymaximum water concentrations are only governed by practicalconsiderations. As noted, treatment conditions such as temperature,pressure and contact time may also vary greatly and any suitablecombination of such conditions may be employed herein. For instance, adecrease in one of such conditions may be compensated for by an increasein one or both of the other conditions, while the opposite correlationis also true. In general liquid temperatures ranging from about 10° C.to about 120° C., preferably from about 20° C. to about 80° C., and morepreferably from about 25° C. to about 60° C. should be suitable for mostinstances, although lower or higher temperatures could be employed ifdesired. As noted above, it has been surprisingly discovered thatminimum loss of organophosphite ligand occurs when a reaction productfluid containing a metal-organophosphite ligand complex catalyst iscontacted with water even at elevated temperatures. Normally thetreatment is carried out under pressures ranging from ambient toreaction pressures and the contact time may vary from a matter ofseconds or minutes to a few hours or more.

Moreover, success in removing phosphorus acidic compounds from thereaction product fluid according to the subject invention may bedetermined by measuring the rate degradation (consumption) of theorganophosphite ligand present in the hydroformylation reaction medium.The consumption rate can vary over a wide range, e.g., from about ≦0.6up to about 5 grams per liter per day, and will be governed by the bestcompromise between cost of ligand and treatment frequency to keephydrolysis below autocatalytic levels. Preferably the water treatment ofthis invention is carried out in such a manner that the consumption ofthe desired organophosphite ligand present in the hydroformylationreaction medium of the hydroformylation process is maintained at anacceptable rate, e.g., ≦0.5 grams of ligand per liter per day, and morepreferably ≦0.1 grams of ligand per liter per day, and most preferably≦0.06 grams of ligand per liter per day. As the extraction of phosphorusacidic compounds into the water proceeds, the pH of the water willdecrease and become more and more acidic. When the water reaches anunacceptable acidity level it may simply be replaced with new water.

The preferred method of operation of this invention is to pass all or aportion of the reaction product fluid before removal of product orreaction product fluid concentration after removal of product throughthe water. Alternately, water may be sprayed into or otherwise added tothe at least one reaction zone or the at least one separation zone toachieve acidity control. The water layer formed may then be separated,e.g., decanted, from the reaction product fluid. An advantage of thisscheme is that extraction capability is immediately available if acidityforms in the reaction product fluid. This invention is not intended tobe limited in any manner by the permissible means for contacting areaction product fluid with water (either inside or outside of thereaction zone or separation zone).

For purposes of this invention, "non-contacted water" is contemplated toinclude water that has not been contacted with the reaction productfluid and "contacted water" is contemplated to include water that hasbeen contacted with the reaction product fluid.

Any means to prepare the non-contacted water for use with the process ofthis invention can be used so long as the water is substantially free ofcatalyst poisons, inhibitors, or compounds that would promoteundesirable side reactions in the catalyst solution. A summary of watertreatment techniques can be found in the Kirk Othmer, Encyclopedia ofChemical Technology, Fourth Edition, 1996.

Water treatment should begin with an evaluation of the water qualityneeds for the process. For acid extraction from reaction product fluidscontaining metal-organophosphite ligand complex catalysts, the qualityof water required is generally of boiler quality or better. Sources ofwater for purification can vary greatly in purity from river watercontaining logs, silt and other debris, to steam condensate that isrelatively pure. If river water is to be used, purification starts withfiltration of the largest pieces. Grates or screens may be used for thisfirst filtration step. A number of techniques can be used to removeother solids that may be present in the water including; sedimentation,centrifugal separation, filtration, coagulation, flocculation, magneticseparation, or combinations of these. After clarified water is obtained,the remaining dissolved solids can also be treated in a number of ways.Distillation is still commonly practiced. Dissolved salts may be treatedwith other acids or bases to precipitate certain compounds. The acids orbases that are added are chosen based on the solubility of the compoundsthat will be produced. Ion exchange is another popular method forremoving dissolved salts. The most common ion exchange method usessodium as the cation. Other ion exchange techniques with protons orhydroxide ions may also be employed. Adsorption can be used to removesome metal salts and organic compounds that may be present. Activatedcarbon is used commonly as an adsorbent. Membranes are still anothertechnique that may be used removed dissolved salts or other colloidalparticles. Membranes separate based on size, electronic charge,hydrophobicity, or other physical-chemical property differences. Reverseosmosis is an example of using membranes to purify water. If dissolvedgases such as oxygen are present, the water can be stripped with steamor nitrogen or subjected to vacuum to remove or replace the dissolvedgas. A preferred process to purify non-contacted water necessary for theacid removal would be a combination of some of the aforementionedtechniques.

Internal techniques where additives are used to counteract the harmfuleffects of impurities can also be used to prepare non-contacted waterfor use in extraction, but the external techniques described in thepreceding paragraph are more preferred.

The contacted water employable in this invention may comprise anysuitable water such that the pH of the contacted water may range fromabout 2 to about 7.5, preferably from about 2.5 to about 7 and morepreferably from about 3 to about 6. The flowrate of water through theextractor and/or the addition of water to the at least one reaction zoneand/or the at least one separation zone should be sufficient to controlpH of the water at desired levels. An increased flowrate of waterthrough the extractor may cause removal, i.e., through the watereffluent, of certain amounts of one or more products from the process.

In a preferred embodiment of this invention, one or more aldehydeproducts removed by water extraction can be recovered and returned tothe hydroformylation process as depicted in the process flow diagram ofFIG. 1. For example, the one or more aldehyde products may be returnedto the hydroformylation process by steam stripping the water effluentfrom the extractor and returning the organic phase of the condensedstripper heads to the hydroformylation process. The aqueous phase of thestripper heads may be returned to the stripper feed. The tails of thestripper may contain the acidic decomposition products from thecatalyst.

In another embodiment, this invention relates to treating at least aportion of the contacted water which contains phosphorus acidiccompounds formed during a process by introducing one or more strongbases into the at least one scrubber zone sufficient to neutralize atleast some amount of the phosphorus acidic compounds contained in saidwater, provided the pH of the contacted water does not exceed 7.5. Thestrong base treated contacted water should have the followingcharacteristics: (i) not reactive with the product; (ii) not so basic asto promote aldol condensation; and (iii) basic salts are water solubleso as to facilitate removal from the reaction zone. Preferably, thecontacted water can be recycled and the product recovered if thephosphorus acidic compounds are neutralized. If the phosphorus acidiccompounds are not neutralized, the contacted water may not be recycledand will most likely go to an effluent waste treatment facility.Illustrative suitable strong bases include, for example, alkali andalkaline earth metal hydroxides, e.g., sodium hydroxide, alkali metalphosphates, e.g., trisodium phosphate, disodium hydrogen phosphate andthe like. The quantity of strong base relative to contacted water willdepend upon the quantity of phosphorus acidic compounds in the contactedwater. The quantity of strong base need only be sufficient to reduce thephosphorus acidic compound concentration to the desired value, providedthe pH of the contacted water does not exceed 7.5.

Optionally, an organic nitrogen compound may be added to the reactionproduct fluid, e.g., hydroformylation reaction product fluid, toscavenge the acidic hydrolysis byproducts formed upon hydrolysis of theorganophosphite ligand, as taught, for example, in U.S. Pat. No.4,567,306. Such organic nitrogen compounds may be used to react with andto neutralize the acidic compounds by forming conversion product saltstherewith, thereby preventing the metal, e.g., rhodium, from complexingwith the acidic hydrolysis byproducts and thus helping to protect theactivity of the metal, e.g., rhodium, catalyst while it is present inthe reaction zone under reaction, e.g., hydroformylation, conditions.The choice of the organic nitrogen compound for this function is, inpart, dictated by the desirability of using a basic material that issoluble in the reaction medium and does not tend to catalyze theformation of aldols and other condensation products at a significantrate or to unduly react with the product, e.g., aldehyde.

Such organic nitrogen compounds may contain from 2 to 30 carbon atoms,and preferably from 2 to 24 carbon atoms. Primary amines should beexcluded from use as said organic nitrogen compounds. Preferred organicnitrogen compounds should have a distribution coefficient that favorssolubility in the organic phase. In general more preferred organicnitrogen compounds useful for scavenging the phosphorus acidic compoundspresent in the reaction product fluid of this invention include thosehaving a pKa value within ±3 of the pH of the contacted water employed.Most preferably the pKa value of the organic nitrogen compound will beessentially about the same as the pH of the water employed. Of course itis to be understood that while it may be preferred to employ only onesuch organic nitrogen compound at a time in any given process, ifdesired, mixtures of two or more different organic nitrogen compoundsmay also be employed in any given processes.

Illustrative organic nitrogen compounds include e.g., trialkylamines,such as triethylamine, tri-n-propylamine, tri-n-butylamine,tri-iso-butylamine, tri-iso-propylamine, tri-n-hexylamine,tri-n-octylamine, dimethyl-iso-propylamine, dimethyl-hexadecylamine,methyl-di-n-octylamine, and the like, as well as substituted derivativesthereof containing one or more noninterfering substituents such ashydroxy groups, for example triethanolamine, N-methyl-di-ethanolamine,tris-(3-hydroxypropyl)-amine, and the like. Heterocyclic amines can alsobe used such as pyridine, picolines, lutidines, collidines,N-methylpiperidine, N-methylmorpholine, N-2'-hydroxyethylmorpholine,quinoline, iso-quinoline, quinoxaline, acridien, quinuclidine, as wellas, diazoles, triazole, diazine and triazine compounds, and the like.Also suitable for possible use are aromatic tertiary amines, such asN,N-dimethylaniline, N,N-diethylaniline, N,N-dimethyl-p-toluidine,N-methyldiphenylamine, N,N-dimethylbenzylamine,N,N-dimethyl-1-naphthylamine, and the like. Compounds containing two ormore amino groups, such as N,N,N',N'-tetramethylethylene diamine andtriethylene diamine (i.e. 1,4-diazabicyclo- 2,2,2!-octane) can also bementioned.

Preferred organic nitrogen compounds useful for scavenging thephosphorus acidic compounds present in the reaction product fluids ofthe this invention are heterocyclic compounds selected from the groupconsisting of diazoles, triazoles, diazines and triazines, such as thosedisclosed and employed in copending U.S. patent application Ser. No.08/756,789, filed on an even date herewith, the disclosure of which isincorporated herein by reference. For example, benzimidazole andbenztriazole are preferred candidates for such use.

Illustrative of suitable organic nitrogen compounds include thosepermissible organic nitrogen compounds described in Kirk-Othmer,Encyclopedia of Chemical Technology, Fourth Edition, 1996, the pertinentportions of which are incorporated herein by reference.

The amount of organic nitrogen compound that may be present in thereaction product fluid for scavenging the phosphorus acidic compoundspresent in the reaction product fluids of the this invention istypically sufficient to provide a concentration of at least about 0.0001moles of free organic nitrogen compound per liter of reaction productfluid. In general the ratio of organic nitrogen compound to totalorganophosphite ligand (whether bound with rhodium or present as freeorganophosphite) is at least about 0.1:1 and even more preferably atleast about 0.5:1. The upper limit on the amount of organic nitrogencompound employed is governed mainly only by economical considerations.Organic nitrogen compound: organophosphite molar ratios of at leastabout 1:1 up to about 5:1 should be sufficient for most purpose.

It is to be understood the organic nitrogen compound employed toscavenge said phosphorus acidic compounds need not be the same as theheterocyclic nitrogen compound employed to protect the metal catalystunder harsh conditions such as exist in the product, e.g., aldehyde,vaporizer-separator, as taught in copending U.S. patent application Ser.No. 08/756,789, referred to above. However, if said organic nitrogencompound and said heterocyclic nitrogen compound are desired to be thesame and perform both said functions in a given process, care should betaken to see that there will be a sufficient amount of the heterocyclicnitrogen compound present in the reaction medium to also provide thatamount of free heterocyclic nitrogen compound in the process, e.g.,hydroformylation vaporizer-separator, that will allow both desiredfunctions to be achieved.

Accordingly the water will not only remove free phosphoric acidiccompounds from the metal-organophosphite ligand complex catalystcontaining reaction product fluids, the water also surprisingly removesthe phosphorus acidic material of the conversion product salt formed bythe use of the organic nitrogen compound scavenger when employed, i.e.,the phosphorus acid of said conversion product salt remains behind inthe water, while the treated reaction product fluid, along with thereactivated (free) organic nitrogen compound is returned to the reactionzone.

Another problem that has been observed when organopolyphosphite ligandpromoted metal catalysts are employed in processes, e.g., continuousliquid catalyst recycle hydroformylation processes, that involve harshconditions such as recovery of the aldehyde via a vaporizer-separator,i.e., the slow loss in catalytic activity of the catalysts is believeddue at least in part to the harsh conditions such as exist in avaporizer employed in the separation and recovery of the aldehydeproduct from its reaction product fluid. For instance, it has been foundthat when an organopolyphosphite promoted rhodium catalyst is placedunder harsh conditions such as high temperature and low carbon monoxidepartial pressure, that the catalyst deactivates at an accelerated pacewith time, due most likely to the formation of an inactive or lessactive rhodium species, which may also be susceptible to precipitationunder prolonged exposure to such harsh conditions. Such evidence is alsoconsistent with the view that the active catalyst which underhydroformylation conditions is believed to comprise a complex ofrhodium, organopolyphosphite, carbon monoxide and hydrogen, loses atleast some of its coordinated carbon monoxide ligand during exposure tosuch harsh conditions as encountered in vaporization, which provides aroute for the formation of catalytically inactive or less active rhodiumspecies. The means for preventing or minimizing such catalystdeactivation and/or precipitation involves carrying out the inventiondescribed and taught in copending U.S. patent application Ser. No.08/756,789, referred to above, which comprises carrying out thehydroformylation process under conditions of low carbon monoxide partialpressure in the presence of a free heterocyclic nitrogen compound asdisclosed therein.

By way of further explanation it is believed the free heterocyclicnitrogen compound serves as a replacement ligand for the lost carbonmonoxide ligand thereby forming a neutral intermediate metal speciescomprising a complex of the metal, organopolyphosphite, the heterocyclicnitrogen compound and hydrogen during such harsh conditions, e.g.,vaporization separation, thereby preventing or minimizing the formationof any such above mentioned catalytic inactive or less active metalspecies. It is further theorized that the maintenance of catalyticactivity, or the minimization of its deactivation, throughout the courseof such continuous liquid recycle hydroformylation is due toregeneration of the active catalyst from said neutral intermediate metalspecies in the reactor (i.e. hydroformylation reaction zone) of theparticular hydroformylation process involved. It is believed that underthe higher syn gas pressure hydroformylation conditions in the reactor,the active catalyst complex comprising metal, e.g., rhodium,organopolyphosphite, carbon monoxide and hydrogen is regenerated as aresult of some of the carbon monoxide in the reactant syn gas replacingthe heterocyclic nitrogen ligand of the recycled neutral intermediaterhodium species. That is to say, carbon monoxide having a strongerligand affinity for rhodium, replaces the more weakly bondedheterocyclic nitrogen ligand of the recycled neutral intermediaterhodium species that was formed during vaporization separation asmentioned above, thereby reforming the active catalyst in thehydroformylation reactor.

Thus the possibility of metal catalyst deactivation due to such harshconditions is said to be minimized or prevented by carrying out suchdistillation of the desired product from the metal-organopolyphosphitecatalyst containing reaction product fluids in the added presence of afree heterocyclic nitrogen compound having a five or six memberedheterocyclic ring consisting of 2 to 5 carbon atoms and from 2 to 3nitrogen atoms, at least one of said nitrogen atoms containing a doublebond. Such free heterocyclic nitrogen compounds may be selected from theclass consisting of diazole, triazole, diazine, and triazine compounds,such as, e.g., benzimidazole or benzotriazole, and the like. The term"free" as it applies to said heterocyclic nitrogen compounds is employedtherein to exclude any acid salts of such heterocyclic nitrogencompounds, i.e., salt compounds formed by the reaction of any phosphorusacidic compound present in the reaction product fluid with such freeheterocyclic nitrogen compounds as discussed herein above.

It is to be understood that while it may be preferred to employ only onefree heterocyclic nitrogen compound at a time in any given process, ifdesired, mixtures of two or more different free heterocyclic nitrogencompounds may also be employed in any given process. Moreover the amountof such free heterocyclic nitrogen compounds present during harshconditions, e.g., the vaporization procedure, need only be that minimumamount necessary to furnish the basis for at least some minimization ofsuch catalyst deactivation as might be found to occur as a result ofcarrying out an identical metal catalyzed liquid recyclehydroformylation process under essentially the same conditions, in theabsence of any free heterocyclic nitrogen compound during vaporizationseparation of the aldehyde product. Amounts of such free heterocyclicnitrogen compounds ranging from about 0.01 up to about 10 weightpercent, or higher if desired, based on the total weight of the reactionproduct fluid to be distilled should be sufficient for most purposes.

An alternate method of transferring acidity from the reaction productfluid to an aqueous fraction is through the intermediate use of aheterocyclic amine which has a fluorocarbon or silicone side chain ofsufficient size that it is immiscible in both the reaction product fluidand in the aqueous fraction. The heterocyclic amine may first becontacted with the reaction product fluid where the acidity present inthe reaction product fluid will be transferred to the nitrogen of theheterocyclic amine. This heterocyclic amine layer may then be decantedor otherwise separated from the reaction product fluid before contactingit with the aqueous fraction where it again would exist as a separatephase. The heterocyclic amine layer may then be returned to contact thereaction product fluid.

For purposes of this invention, the term "hydrocarbon" is contemplatedto include all permissible compounds having at least one hydrogen andone carbon atom. Such permissible compounds may also have one or moreheteroatoms. In a broad aspect, the permissible hydrocarbons includeacyclic (with or without heteroatoms) and cyclic, branched andunbranched, carbocyclic and heterocyclic, aromatic and nonaromaticorganic compounds which can be substituted or unsubstituted.

As used herein, the term "substituted" is contemplated to include allpermissible substituents of organic compounds unless otherwiseindicated. In a broad aspect, the permissible substituents includeacyclic and cyclic, branched and unbranched, carbocyclic andheterocyclic, aromatic and nonaromatic substituents of organiccompounds. Illustrative substituents include, for example, alkyl,alkyloxy, aryl, aryloxy, hydroxy, hydroxyalkyl, amino, aminoalkyl,halogen and the like in which the number of carbons can range from 1 toabout 20 or more, preferably from 1 to about 12. The permissiblesubstituents can be one or more and the same or different forappropriate organic compounds. This invention is not intended to belimited in any manner by the permissible substituents of organiccompounds.

Certain of the following examples are provided to further illustratethis invention.

EXAMPLE 1

Into a glass vessel was added a stock solution of 536 parts per millionof hydroxy butyl phosphonic acid in butyraldehyde. This solution wascontacted with water in a weight ratio of 1.18:1 grams water to gramsaldehyde/acid stock solution. The aldehyde and water phase werecontacted thoroughly to allow the separation of acid between the organicand the aqueous layer to reach equilibrium. The aldehyde phase wasanalyzed for hydroxy butyl phosphonic acid by ion chromatography aftercontact with the water giving 52.3 parts per million of hydroxy butylphosphonic acid. The water phase was also analyzed by ion chromatographyfor the acid. The water phase contained 414 parts per million of hydroxybutyl phosphonic acid. The partition coefficient between the water andthe butyraldehyde phase was 414/52.3 or 7.92.

EXAMPLE 2

This control example illustrates the stability of Ligand F (asidentified herein) in a solution containing 200 parts per million ofrhodium, and 0.39 percent by weight of Ligand F in butyraldehydecontaining aldehyde dimer and trimer in the absence of added acid orbenzimidazole.

To a clean, dry 25 milliliter vial was added 12 grams of thebutyraldehyde solution mentioned above. Samples were analyzed for LigandF using High Performance Liquid Chromatography after 24 and 72 hours.The weight percent of Ligand F was determined by High Performance LiquidChromatography relative to a calibration curve. No change in theconcentration of Ligand F was observed after either 24 or 72 hours.

EXAMPLE 3

This Example is similar to Example 2 except that phosphorus acid wasadded to simulate the type of acid that might be formed duringhydrolysis of an organophosphite.

The procedure for Example 2 was repeated with the modification of adding0.017grams of phosphorous acid (H₃ PO₃) to the 12 gram solution. After24 hours the concentration of Ligand F had decreased from 0.39 to 0.12percent by weight; after 72 hours the concentration of Ligand F haddecreased to 0.04 percent by weight. This data shows that strong acidscatalyze the decomposition of Ligand F.

EXAMPLE 4

This Example is similar to Example 2 except that both phosphorus acidand benzimidazole were added.

The procedure for Example 2 was repeated with the modification of adding0.018 grams of phosphorous acid and 0.0337 grams of benzimidazole to thesolution. No decomposition of Ligand F was observed after either 24 or72 hours. This shows that the addition of benzimidazole effectivelybuffers the effect of the strong acid and thereby prevents the rapiddecomposition of Ligand F.

EXAMPLE 5

The following series of experiments were performed in order to determinethe relationship of the pKa of a base to the effectiveness of the baseto remain in the organic phase upon contact with an equimolar aqueousacid solution. In all cases the experiments were performed undernitrogen, unless otherwise specified.

Solutions were prepared by dissolving a quantity of acid or base insolvent so that the final concentration was equal to 0.1 moles/liter.The 1×10⁻³ moles/liter solutions were prepared by taking an aliquot ofthe 0.1 moles/liter solution and diluting to the specifiedconcentration. The 1×10⁻⁵ moles/liter solutions were prepared in thesame manner as the 1×10⁻³ moles/liter solution with the modification ofusing an aliquot of the 1×10⁻³ moles/liter solution in place of the 0.1moles/liter solution.

In each extraction experiment, 5 milliliters of base solution inbutyraldehyde was added to a clean, dry vial. To this vial was added 5milliliters of equimolar H₃ PO₃ solution. The resulting mixture wasrapidly shaken for several minutes and then allowed to phase separate. A1 milliliter aliquot of the aqueous layer was then transferred to aclean, dry vial. To this vial was added 1 milliliter of pH 7sodium/potassium phosphate buffer and 0.1 milliliter of Tergitol® 15-S-9surfactant. The solution was shaken vigorously, and an aliquot wasanalyzed by high performance liquid chromatography for base content. Theamount of base was then compared with a dichloromethane solution at theinitial concentration. The partition coefficients calculated are forpartitioning of the base from the organic phase to the water phase andis defined as K=amount of base in the water phase/amount of base in theorganic phase. The results of the extraction experiment are summarizedin Table A.

                  TABLE A                                                         ______________________________________                                                       pKa    Concentrati   Concentrati                                              of     on            on                                        Run  Base      base   (moles/liter)                                                                         Acid  (moles/liter)                                                                         K                                 ______________________________________                                        1    2-benzyl- 5.1    1 × 10.sup.-3                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-3                                                                   0.22                                   pyridine                                                                 2    2-benzyl- 5.1    1 × 10.sup.-5                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-5                                                                   0.30                                   pyridine                                                                 3    quinoline 4.8    1 × 10.sup.-3                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-3                                                                   0.43                              4    quinoline 4.8    1 × 10.sup.-5                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-5                                                                   1.20                              5    3-acetyl- 3.3    1 × 10.sup.-3                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-3                                                                   0.93                                   pyridine                                                                 6    3-acetyl- 3.3    1 × 10.sup.-5                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-5                                                                   0.00                                   pyridine                                                                 7    benzotriazole                                                                           1.6    1 × 10.sup.-3                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-3                                                                   0.08                              8    benzotriazole                                                                           1.6    1 × 10.sup.-5                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-5                                                                   0.00                              9    1-benzyl- -0.7   1 × 10.sup.-3                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-3                                                                   0.02                                   2-pyrroli-                                                                    dinone                                                                   10   1-benzyl- -0.7   1 × 10.sup.-5                                                                   H.sub.3 PO.sub.3                                                                    1 × 10.sup.-5                                                                   0.00                                   2-pyrroli-                                                                    dinone                                                                   ______________________________________                                    

The results show that the smaller the pKa of the base, the more remainsin the organic phase.

Although the invention has been illustrated by certain of the precedingexamples, it is not to be construed as being limited thereby; butrather, the invention encompasses the generic area as hereinbeforedisclosed. Various modifications and embodiments can be made withoutdeparting from the spirit and scope thereof.

We claim:
 1. A process for separating one or more phosphorus acidiccompounds from a reaction product fluid containing said one or morephosphorus acidic compounds, a metal-organophosphite ligand complexcatalyst and optionally free organophosphite ligand which processcomprises treating said reaction product fluid with water sufficient toremove at least some amount of said one or more phosphorus acidiccompounds from said reaction product fluid, wherein said reactionproduct fluid comprises an organic phase and said water comprises aseparate aqueous or water phase.
 2. A process for stabilizing anorganophosphite ligand against hydrolytic degradation and/or ametal-organophosphite ligand complex catalyst against deactivation whichprocess comprises treating a reaction product fluid containing ametal-organophosphite ligand complex catalyst and optionally freeorganophosphite ligand and which also contains one or more phosphorusacidic compounds, with water sufficient to remove at least some amountof said one or more phosphorus acidic compounds from said reactionproduct fluid, wherein said reaction product fluid comprises an organicphase and said water comprises a separate aqueous or water phase.
 3. Aprocess for preventing and/or lessening hydrolytic degradation of anorganophosphite ligand and/or deactivation of a metal-organophosphiteligand complex catalyst which process comprises treating a reactionproduct fluid containing a metal-organophosphite ligand complex catalystand optionally free organophosphite ligand and which also contains oneor more phosphorus acidic compounds, with water sufficient to remove atleast some amount of said one or more phosphorus acidic compounds fromsaid reaction product fluid, wherein said reaction product fluidcomprises an organic phase and said water comprises a separate aqueousor water phase.
 4. An improved process which comprises reacting one ormore reactants in the presence of a metal-organophosphite ligand complexcatalyst and optionally free organophosphite ligand to produce areaction product fluid comprising one or more, the improvementcomprising preventing and/or lessening hydrolytic degradation of anysaid organophosphite ligand and deactivation of saidmetal-organophosphite ligand complex catalyst by treating at least aportion of said reaction product fluid derived from said process andwhich also contains phosphorus acidic compounds formed during saidprocess with water sufficient to remove at least some amount of thephosphorus acidic compounds from said reaction product fluid, whereinsaid reaction product fluid comprises an organic phase and said watercomprises a separate aqueous or water phase.
 5. The improved process ofclaim 4 which comprises (i) reacting in at least one reaction zone oneor more reactants in the presence of a metal-organophosphite ligandcomplex catalyst and optionally free organophosphite ligand to produce areaction product fluid comprising one or more products and (ii)separating in at least one separation zone or in said at least onereaction zone the one or more products from said reaction product fluid,the improvement comprising preventing and/or lessening hydrolyticdegradation of any said organophosphite ligand and deactivation of saidmetal-organophosphite ligand complex catalyst by (a) withdrawing fromsaid at least one reaction zone or said at least one separation zone atleast a portion of said reaction product fluid derived from said processand which also contains phosphorus acidic compounds formed during saidprocess, (b) treating in at least one scrubber zone at least a portionof the withdrawn reaction product fluid derived from said process andwhich also contains phosphorus acidic compounds formed during saidprocess with water sufficient to remove at least some amount of thephosphorus acidic compounds from said reaction product fluid, and (c)returning the treated reaction product fluid to said at least onereaction zone or said at least one separation zone.
 6. The improvedprocess of claim 4 which comprises (i) reacting in at least one reactionzone one or more reactants in the presence of a metal-organophosphiteligand complex catalyst and optionally free organophosphite ligand toproduce a reaction product fluid comprising one or more products and(ii) separating in at least one separation zone or in said at least onereaction zone the one or more products from said reaction product fluid,the improvement comprising preventing and/or lessening hydrolyticdegradation of any said organophosphite ligand and deactivation of saidmetal-organophosphite ligand complex catalyst by treating at least aportion of said reaction product fluid derived from said process andwhich also contains phosphorus acidic compounds formed during saidprocess by introducing water into said at least one reaction zone and/orsaid at least one separation zone sufficient to remove at least someamount of the phosphorus acidic compounds from said reaction productfluid.
 7. The process of claim 4 which comprises a hydroformylation,hydroacylation (intramolecular and intermolecular), hydrocyanation,hydroamidation, hydroesterification, aminolysis, alcoholysis,carbonylation, isomerization or transfer hydrogenation process.
 8. Theprocess of claim 6 wherein the water introduced into said at least onereaction zone and/or said at least one separation zone is an amountsufficient to produce a separate aqueous or water phase in addition toan organic phase.
 9. The process of claim 6 further comprisingseparating the water from the reaction product fluid.
 10. The process ofclaim 1 wherein the contacted water has a pH of from 2 to 7.5.
 11. Theprocess of claim 5 in which the water after treating in step (b)contains one or more aldehydes.
 12. The process of claim 11 furthercomprising recovering said one or more aldehydes from the water aftertreating in step (b) and returning the recovered one or more aldehydesto said at least one reaction zone or said at least one separation zone.13. The process of claim 4 wherein said metal-organophosphite ligandcomplex catalyst is homogeneous or heterogeneous.
 14. The process ofclaim 4 wherein said reaction product fluid contains a homogeneous orheterogeneous metal-organophosphite ligand complex catalyst or at leasta portion of said reaction product fluid contacts a fixed heterogeneousmetal-organophosphite ligand complex catalyst during said process. 15.The process of claim 4 wherein said separating of one or more productsfrom the reaction product fluid occurs prior to or after treating atleast a portion of the reaction product fluid derived from said processand which also contains phosphorus acidic compounds formed during saidprocess with water.
 16. The process of claim 4 further comprisingtreating the contacted water which contains phosphorus acidic compoundswith a strong base sufficient to neutralize at least some amount of thephosphorus acidic compounds.
 17. The process of claim 1 wherein saidmetal-organophosphite ligand complex catalyst comprises rhodiumcomplexed with an organophosphite ligand selected from:(i) amonoorganophosphite represented by the formula: ##STR31## wherein R¹represents a substituted or unsubstituted trivalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms or greater; (ii) adiorganophosphite represented by the formula: ##STR32## wherein R²represents a substituted or unsubstituted divalent hydrocarbon radicalcontaining from 4 to 40 carbon atoms or greater and W represents asubstituted or unsubstituted monovalent hydrocarbon radical containingfrom 1 to 18 carbon atoms or greater; (iii) a triorganophosphiterepresented by the formula: ##STR33## wherein each R⁶ is the same ordifferent and represents a substituted or unsubstituted monovalenthydrocarbon radical; and (iv) an organopolyphosphite containing two ormore tertiary (trivalent) phosphorus atoms represented by the formula:##STR34## wherein X represents a substituted or unsubstituted n-valenthydrocarbon bridging radical containing from 2 to 40 carbon atoms, eachR⁷ is the same or different and represents a divalent hydrocarbonradical containing from 4 to 40 carbon atoms, each R⁸ is the same ordifferent and represents a substituted or unsubstituted monovalenthydrocarbon radical containing from 1 to 24 carbon atoms, a and b can bethe same or different and each have a value of 0 to 6, with the provisothat the sum of a+b is 2 to 6 and n equals a+b.
 18. The process of claim4 wherein phosphorus acidic compounds present in the reaction productfluid are scavenged by an organic nitrogen compound that is also presentin said reaction product fluid and wherein at least some amount of thephosphorus acidic compound of the conversion products of the reactionbetween said phosphorus acidic compound and said organic nitrogencompound are also removed by the water treatment.
 19. The process ofclaim 18 wherein the organic nitrogen compound is selected from thegroup consisting of diazoles, triazoles, diazines and triazines.
 20. Theprocess of claim 19 wherein the organic nitrogen compound isbenzimidazole or benzotriazole.